Gravity Expeditions at Sea

The K-XVIII expedition was a Dutch geodetic and geophysical expedition to East Indies from 14 November 1934 until 11 July 1935. On board was the Dutch scientist Felix Andries Vening Meinesz with his pendulum apparatus the ‘Golden Calf’ to measure the gravity field of the Earth.

Professor Vening Meinesz left the port of Den Helder along with captain D.C.M. Hetterschij and 33 sailors aboard the submarine HNLMS K-XVIII. This would be the longest expedition Vening Meinesz ever made aboard a submarine. The K-XVIII’sfinal destination was Surabaya, but instead of the normal route via the Suez Canal, the submarine visited several continents along the way, taking a detour that took eight months. The K-XVIII arrived at Surabaya in July 1935 after travelling over 23.000 miles across the Earth’s oceans. The Royal Netherlands Navy and Vening Meinesz had worked together on other expeditions before, but this was the most spectacular journey.

Felix Andries Vening Meinesz

Felix Andries Vening Meinesz (The Hague July 30, 1887 - Amersfoort August 10, 1966) was a Dutch geophysicist and geodesist. He is known for his invention of a precise method for measuring gravity on a moving vessel. Thanks to his invention, it became possible to measure gravity at sea, which led him to the discovery of gravity anomalies above the ocean floor.

Equipment

Several instruments were on board the K-XVIII to perform geo-scientific experiments and observations. The famous pendulum apparatus of Vening Meinesz, named by previous sailors ‘Golden Calf’, measured the gravity field on the seas. For land-based observations, Vening Meinesz took the Holweck-Lejaygravimeter, which was lent by the Bataafsche Petroleum Maatschappij, later Shell. The Navy had installed the brand new ‘Alas echo lood’, which had a precision of around 30 meters. Several high accurate chronometers, like the Nardin 212, were on board to facilitate the gravity measurements and determination of the position. Furthermore, prof. dr. J. Clay gave Vening Meinesz an experimental setup to measure cosmic radiation, however this failed to work during the expedition.

The Royal Dutch Navy

The Royal Dutch Navy used this journey to wave the flag abroad, to improve its reputation in the Netherlands and to test the abilities of the crew. The submarine also functioned as a beacon for the Fokker KXVIII ‘Snip’Christmas mail flight across the Atlantic Ocean. The K-XVIIIwas under the command of lieutenant commander D.C.M. Hetterschij. He was in charge of the complete mission, which entailed waving the flag, training the crew and inspecting the economic situation of the island Tristan da Cunha and its inhabitants.

Media coverage

There was a lot of media coverage in the Dutch press and even foreign newspapers wrote multiple articles when the submarine visited their port. This coverage was instigated by the comity Onze Marine. Both this comity and lieutenant M.S. Wytema wrote a book about this extraordinary journey. Wytema filmed life on board the submarine during this extraordinary expedition. The Polygon movie “20,000 mijlen over zee – De wereldreis van onderzeeboot K-XVIII” went in premiere January of 1936

Results

During this particular expedition, a number of 240 measurements of the gravity field at sea and 30 land-based gravimetric observations were obtained. It allowed professor Vening Meinesz to study the behaviour of continental isostasy. He was able to come up with is famous regional isostatic theory, which perfectly explains the support of volcanic islands. His observations gave the first insight that the volcanic mid-Atlantic Ridge was a different phenomenon than the observed volcanic arcs in the Caribbean and East Indies. He measured deep scars in the oceanic floor, supporting of volcanic islands, and large negative anomalies at volcanic island arcs. His systematic planning and elaborate calibration, together with his collaboration with the Dutch Navy, changed the way scientific expeditions were performed. After Vening Meinesz’ expeditions a new era of oceanographic research was started.

Departure Den Helder

The K-XVIII departed on 14 November 1934 from the Dutch Navy harbor in Den Helder to commence the longest solo mission for a submarine. On board the K-XVIII was professor Vening Meinesz.

After months of preparations, the K-XVIII left the port of Den Helder for the longest journey with a submarine ever made. The submarine would travel over 23.000 miles during eight months to its final destination, Surabaya. Ships would normally cross the Suez Canal, but the K-XVIII would use a different route. It took a detour via West Africa, South-America, South Africa and Western Australia. The journey had several goals, which were mentioned by rear admiral, T. L. Kruijs, at the departure ceremony:

Crew of the Hr. Ms. K18, you will experience the longest journey ever made with a submarine. The goal of this journey is to add the K 18 to the fleet of the Dutch Navy in the East Indies. Furthermore, this trip will enable professor Vening Meinesz to extend his important observations concerning gravity. Finally, you will serve as a beacon for the planned KLM Christmas-mail flight to West Indie.

Other goals were the improvement of the reputation of the Royal Dutch Navy and waving the flag abroad. Newspapers had frequently reported on the expedition during the months leading up to the departure, which resulted in a large number of people waving the crew goodbye. This time, it was not just family members interested to know about the men, a whole nation would read every news article on the K-XVIII for the following months.

Gravity Explained

The goal of Vening Meinesz was to measure the gravity field of the Earth. What is gravity and why does it differ on various locations.

Professor Vening Meinesz undertook his numerous submarine-expeditions to measure the gravity field of the Earth, but what is gravity and why did he need to measure it at different locations around the globe? It was Isaac Newton (1687), who provided the definition of the gravitational force:

Every point mass attracts every single other point mass by a force pointing along the line intersecting both points. The force is proportional to the product of the two masses and inversely proportional to the square of the distance between them.

The gravitational force depends on the masses of the objects and the distance between them. Every object with mass attracts other objects with mass. Newton also stated that a force put upon an object is equal to the mass of that object times the acceleration of the object. So, objects are accelerated due to the presence of a gravitational force, which is called gravitational acceleration, or gravity. This acceleration was what Vening Meinesz was interested in. During the voyage of the K-XVIII, he measured the gravity 240 times, as is shown in Figure 1.

The gravity fluctuates between 9.78 and 9.81 m/s2 for this particular expedition, but the pattern seems random. We need to ask why the gravity is fluctuating with respect to the location of the Earth. From Newton, we know that the measured gravity is only dependent on the mass of the Earth and the distance between the center of the Earth and the submarine. The submarine is cruising at a depth of 30 meters below the ocean’s surface during the observations. However, we need to consider that the Earth is not a perfect sphere. Due to its rotation and its viscous nature, the equator of the Earth is rotated outwards, whereas the poles are pulled inward. This effect deforms the surface of the Earth into an oblate spheroid, or flattened sphere. The distance between the center of the Earth and the equator is 6384 km, whereas the poles are at 6353 km distance from the center, a difference of 31 km.

This shape can be noticed if we re-arrange the measurements of Vening Meinesz. Instead of plotting the measurements in chronological order, we can plot the measurements with respect to their latitude, which is their north-south location on the Earth.

Now, a clear pattern can be seen in the gravity measurements. A nearly perfect parabolic relation is observed, instead of the seemingly randomness of the data in the first graph. At the poles, where the latitude is 0 degree, the gravity is lowest, because of the larger distance to the center of the Earth, whereas gravity increases in magnitude at the higher latitudes nearing the poles. This illustrates that you can measure the shape of the Earth by performing gravity observations.

Aboard K-XVIII

The crewmembers on board the K-XVIII had to live in a cramped submarine for eight months. This meant they had to adjust to each other and the circumstances.

The crew covered a great distance over eight months, visiting many places they had never seen before. There were officers of different ranks, Vening Meinesz, several seamen and one marine aboard the K-XVIII. During these eight months, the thirty-five men lived aboard a cramped submarine. Because space was limited, it had to be creatively used. During the day, the rooms were meant as a living space, but in the evening these had to be converted into sleeping-accommodations. The cook had one little stove in the corner of the forward torpedo room to prepare a meal for thirty-five hungry seamen. Most of the crewmembers had four hours watch, but had to perform duties during other hours as well. The ship had to be cleaned between seven o’clock and eleven thirty and again in the afternoon between one and four o’clock. The men had time for themselves when all duties were done and when they were not on watch. One can imagine they were excited to arrive at a port and leave the submarine to stay at a hotel for several days. Moreover, the local citizens had planned some excursions to entertain the visitors from the Netherlands.

Isostasy Explained

Vening Meinesz discovered, during his many expeditions that the strength of the crust is partially responsible for supporting mountains and continents.

One of the most famous theories of Professor Vening Meinesz is about the isostasy of the Earth’s crust. The crust is in an almost perfect state of isostatic equilibrium, which means that the crust is balanced between its gravitational force and the buoyancy force of the mantle. The crust floats atop of the mantle, just like a ship or iceberg floats in the water. On January 25 1855, the British astronomer G. B. Airy sent his paper to the Royal Society on the same equilibrium problem that J. H. Pratt had discussed before the same society on December 7 1854. Both Pratt and Airy had devised a theory that explained why mountains do not sink due to their weight into the deep depths of the Earth.

The Airy isostasy model compensates the extra topographic load by introducing a low-density root underneath the load. This low-density root introduces extra buoyancy, which holds up the load. The same principle is seen in a floating iceberg, where the tip is kept afloat by a large root underneath the surface.

The Pratt isostasy model compensates the topographic load by changing the density of the entire column up to a certain compensation depth. This can be likened to rising dough, where a greater surface load results in more air being trapped in the dough and thus a reduced density. Both Airy and Pratt assumed local isostasy and neglected the influences of regional effects.

Vening Meinesz took the theory one step further and introduced the idea of regional compensation. Instead of taking local mass columns, as Airy and Pratt did, Vening Meinesz postulated that the bending strength of the crust needed to be taken into account.

The gravitational force was not only compensated by the buoyancy force, but also by the support of a bending plate (the crust). The entire region around the topographic load is responsible for the compensation, not just the masses exactly underneath.

His isostasy model proved to be especially powerful in the explanation for the gravity-anomalies measured on volcanic islands. During his previous voyage with the K-XIII submarine; the professor measured the gravity field of Hawaii.

Crossing of the Snip

One of the objectives of the K-XVIII was to be a navigational beacon for KLM’s first trans-continental postal flight. Thanks to the K-XVIII it could safely cross the Atlantic Ocean.

The direction of the voyage of the K-XVIII at this point is a bit strange. After inspection of the navigation logbook of the captain, it became clear they stayed at one location for a whole day before they reached the ridge. This was strange because the location had no significant geophysical relevance (just another submarine volcanic landscape). The comments made by Vening Meinesz in his summaries of the voyage, made it more clear:

Leaving St. Vincent, our route brought us far out into the Atlantic. This loop was due to the crossing of a Dutch plane to the Netherlands Antilles. To provide this plane with the necessary radio-bearings for its position and to give it indications about the weather, Hr. Ms. K18 had to be stationed for twenty-four hours at a certain location in the middle of the ocean.

Netherlands Antilles was Curacao in particular. What aircraft? It was the KLM’s maiden voyage to the West Indies. A Fokker F18, called the “Snip”, made an eight-day voyage from Amsterdam to Curacao. The promotion poster from that time shows the route of the Fokker F18:

It states “KLM Christmas Mail-Flight to Dutch West-Indie, leaving from Schiphol on the 15th of December 1934”. The Fokker F18 would eventually land in Curacao on the 22th of December. This means that it flew over the K-XVIII around the 20th, which coincides with the logbook. If you look closely at the poster, you can see a small (submarine-shaped) figure in the middle of the Atlantic. Could this be the Hr. Ms. K-XVIII with Vening Meinesz onboard? It is drawn slightly more to the southwest, but is a beautiful detail nonetheless. The KLM Fokker F18 voyage would be the start of the famous inter-continental KLM airlines. This is a nice example of two important voyages in Dutch history crossing paths, where K-XVIII provided bearings and weather reports to the Snip.

Plate Tectonics

The theory of plate tectonics was not yet accepted by the academic society during Vening Meinesz time. He did not believe in it, but his observations tell a different story.

The theory of plate tectonics was not generally accepted at the time of Vening Meinesz. In fact, there were two camps. The “mobilists” believed in the plate theory as introduced by Alfred Wegener in 1912, whereas the “fixists” believed that the entire crust could not break and was a single solid piece. Vening Meinesz and the entire Dutch scientific society were “fixists” and did not believe that the rigid crust could break at all. However, the close relationship between Vening Meinesz and Harry Hess, who played a substantial role in the acceptance of plate tectonics, shows that the Vening Meinesz kept an open mind.

The theory of plate tectonics states that the surface of the Earth consists of several individual rigid plates. These plates move or float on a viscous mantle, and due to convection in the mantle, all move relative to each other. Three phenomena appear at the boundaries of these plates, due to the relative motion with respect to each other.

1. Divergent motion: Spreading Ridge
2. Convergent motion: Subduction Zone
3. Transverse motion: Transform Faulting

The ‘Wilson Cycle’, by Tuzco Wilson (1966), describes the creation and destruction of such plates and beautifully explains many geological observations. To find out more about the beauty of this theory, please visit the wikipedia page on plate tectonics .

The Figure shows the main rigid plates of the Earth. The largest plate is the Pacific Oceanic plate, which almost completely covers the entire Pacific Ocean. The continents are situated on their separate plates; however this was not always the case in the distant past. Supercontinents like Gondwana were once the face of the Earth.

Neptune's Ritual

Crossing the equator with a ship could attract the god of the ocean to come aboard. Neptune and his wife visited the K-XVIII, when they crossed the equator on the 11th of January 1935.

It was an age-old tradition aboard ships that passed the equator. Neptune came aboard to perform a crossing-the-line initiation-rite for the seamen that crossed the equator for the first time. A.J. Marcus, J.A. Hiestand, W.A. Wahlers, H. Karstanje, G.J.C. Stolk, G. Heymen and K.E.J. Watz experienced the ritual aboard the K-XVIII on January 11th. Commander Hetterschij welcomed Neptune and his wife, Zeeroosje,before the initiation took place. The men were lathered up and shaven with a large, wooden razor by Neptune, before they received their new nickname. These nicknames were inspired by the sea life or the weather. The men had to crawl underneath a canvas, from which they were welcomed with more mud and sludge by the other crewmembers. At the end, all the men were hosed down and received a certificate to remind them of their initiation.

Romanche Trench

The Romanche Trench is more than seven km deep and located between Africa and South America. The trench is formed, where two plates move along each other, constructing a transform fault.

On the 11th of January 1935, the K18 sailed over the Romanche Trench. It would be the most negative gravity-observation of the professor during the voyage. The professor knew about this mysterious depth in the ocean, as a French Polar Expedition on the vessel “Romanche” discovered it 52 years earlier. However, the nature of this incredible trench was not known. The professor theorized about the subject in his “Gravity Expeditions at Sea Vol. IV” as follows:

None of the gravity profiles gives any indication of great tectonic phenomena in this area. It seems indicated, therefore, to think of a volcanic origin of this remarkable feature in the mid ocean and to interpret it as a huge caldeira.

If the professor had crossed the Romance Trench from east to west, he might have concluded otherwise. Later, it was shown that the Romanche Trench is part of a global system of faults that is needed for plate motion. The Romanche Trench is now known to be a transform fault, which was defined by Wilson (1966) in one of his famous papers that explained the complete plate tectonic cycle.

A transform fault is one of the three types of continental faults, where the subduction fault and the spreading fault are the other types. The transform fault has a strike-slip nature, where two plates scrape each other in opposite direction. Despite the movement of the plates, the length of the transform fault does not change. For more information, please click here . Although the professor misinterpreted the nature of the Romanche Trench, his measurements, yet again, showed remarkable structures in the oceanic bathymetry and gravity field, which would have scientists be working on for many years.

Waving-the-flag

During this time the reputation of the Dutch Navy was very low among the Dutch citizens. The Navy used this expedition to improve this reputation in the Netherlands.

The reputation of the Royal Netherlands Navy was at a low point in 1934 and needed to be improved. The Navy used the journey of the K-XVIII to improve its status in the Netherlands and abroad. The submarine visited many places that had a special bond with the Netherlands during the time of the Vereenigde Oostindische Compagnie (VOC). By visiting these places and making contact with the local Dutch citizens, the navy tried to return to the glory days of the country. The crew and Vening Meinesz engaged in lots of activities during their stay. They were invited for dinners, lectures and outings. At these lectures, the officers and the professor explained about their native country and the Dutch scientific research. All these activities were reported in local and Dutch newspapers and helped improve the Navy’s reputation. At the same time, the officers contacted the local Navies in an effort to get an order to build them submarines. The K-XVIII had to be in perfect condition to impress the foreign delegations. The crew gave several tours and showed the visitors the fast diving procedure. Even though the South-American Navies were impressed by the Dutch design, they did not buy a submarine in the end due to budget cuts.

Biography Vening Meinesz

Professor Vening Meinesz has achieved a lot during his life. His dedication to science played a major role in his life and he has influenced many scientists throughout the world.

Felix Andries Vening Meinesz was born in Scheveningen on 30 July 1887. He was the youngest son of Sjoerd Vening Meinesz and Cornelia Anna Clasina den Tex and became a famous geophysicist and geodesist in the Netherlands. He started his career studying civil engineering at the Delft University of Technology, where he graduated in 1910. He was immediately offered a job at the “The Netherlands Geodetic Committee” (Dutch: Rijkscommissie voor graadmetingen en waterpassing)to measure the strength of the gravitational field in the Netherlands. He finished his research with his thesis ‘Contribution to the theory of pendulum observations’ and received his doctorate cum laude. He then turned from land to sea. He was able to persuade the Royal Netherlands Navy to take him aboard a submarine to perform measurements. This collaboration turned out to be a success and many expeditions would follow. One of the most successful and well-known expeditions was the journey with the K-XVIII in 1934-1935. This voyage was covered by the media and made Vening Meinesz a well-known figure in the Netherlands. He received many requests to speak at local gatherings, but he had to limit these lectures to one reading per city. The professor didn’t embark on submarines again, but he consulted with other scientists and published many books. Vening Meinesz stayed involved until his death on 10 August 1966.

Timeline career

• 1904 Hogereburgerschool (HBS) Amsterdam
• 1905 Student Civil Engineering at Delft University of Technology
• 1910 Graduated Civil Engineering
• Employed by Rijkscommissie voor graadmeting en waterpassing to the strength of gravitational fields in the Netherlands
• 1915 Thesis: cum laude; supervisor: J. Cardinaal.
• 1923-1939 Expeditions aboard submarines
• 1923-1928 Development of the ‘Golden Calf’
• 1927 Endowed professor geodesy, cartography and geophysics at University Utrecht. Member of the Rijkscommissie voor graadmeting en waterpassing
• 1933-1955 President International Association Geodesy.
• 1936 Foreign Member of the Royal Society of London
• 1937 Part-time lector Delft University of Technology. Curator Royal Netherlands Meteorological Institute (Koninklijk Nederlands Metereologisch Instituut, KNMI)
• 1939 Endowed professor geodesy Delft University of Technology
• 1945-1951 Director KNMI
• 1948 Publication research results
• 1948-1951 President International Union of Geodesy and Geophysics
• 1952-1966 Chairman Board of Governors KNMI
• 1957 Emeritus professor

Did you know?

• His father was born as Sjoerd Meinesz, but added Vening in 1893. Vening was his mother’s name.
• His mother’s family belonged to the Dutch nobility
• Felix Vening Meinesz was the youngest of the family? He had two surviving brothers and one sister.
• He was a member of the Student Society Delftsch Studenten Corps
• Vening Meinesz never married. He was married to the job. He was travelling at least 6 months a year and had to process his measurements when he got home.
• He was over two meters (78.74 inch) long: must have been real tight aboard a submarine
• He was Honorary member Vereniging van Utrechtse Geografie Studenten (V.U.G.S.)
• Vening Meinesz received four royal decorations and six medals of honour! (Including: William Bowie medal, Penrose medal, de Plancius medal en de Vetlesen prize)
• He had honorary degrees at the universities of Liège, Helsinki, Brussels, Strasbourg and Columbia (New York).
• He was a Member Royal Netherlands Academy of Arts and Science
• That a street, a lunar crater, a volcanic belt and a university institute for geophysics in Utrecht were named after him
• He travelled more than 100.000 miles at sea, performing over 1000 measurements in 16 years.
• One of his houses was in Amersfoort and still exists today. He inherited the Eelerberg estate from his parents
• He tried to bridge the gap between geophysicists and geodesists
• He wrote several manuals for his students
• He brought his cheap camera with him at excursions. A.A. Menten claimed he took beautiful pictures and he liked the simplicity of his camera.

Expeditions

• 1923 K.II To the Dutch-Indies via Suez Canal
• 1925 K.XI Vening Meinesz until Tunis
• 1926-1927 K.XIII To the Dutch-Indies via Panama Canal
• 1927 K.XIII To Christmas Island (350 km south of
• Java) > Java oceanic trench
• 1928 S.21 (US Navy) Gulf of Mexico
• 1929-1930 K.XIII Indonesian Archipelago
• 1931 Sommrtgibili, crociera, “Vettor Pisani” (Italian Submarine) Mediterranean Sea
• 1931 (juli) O.12 North Sea
• 1932 (januari) S.48 (US Navy) Bahamas; (zomer) O.13 Atlantic Ocean
• 1933 sous-marine “Fresnel” Mediterranean Sea.
• 1934-1935 K.XVIII Netherlands-Dakar-South America-Cape town. Mauritius – Australia – Java
• 1937 O.16 Lisbon via Washington (V.S.)
• 1938 O.12 Curacao to Nederland
• 1939 O.13 English Chanel

K-XVIII Submarine

Thanks to an incredible design and engineering of the K-XVIII, this vessel was able to sail the Earth’s oceans and complete a trip of 23,000 miles.

The K-XVIII is a single-cylinder pre-WWII submarine, designed to operate in the tropical waters of the Dutch Indies. It was designed by ir. J.J. van der Struyff (1865 - 29 December 1933) and constructed in the docks of Fijenoord, Rotterdam. From June 1931 until September 1932, the K-XVIII took shape in yard No. 323, where it was finally launched on the 27th of September 1932. On the 1st of July 1933, captain Hetterschij declared the K-XVIII ready for test sailing.

Saturday 1st of Juli 1933 – Vessel is declared ready for test operations by Commander D.C.M. Hetterschij in agreement with the construction docks – Wytema

In those days, these submarines were built according to hand-drawn blueprints, because programmable computers had yet to be invented. Also the strength and construction calculations were done by hand. These drawings can be viewed with the following link

[Link to the 3D model of the K-XVIII].

Captain Hetterschij was the first commanding officer of the K-XVIII with orders to sail the newly constructed submarine to the East Indies. The K-class submarines were designed for the colonial waters (Dutch: “Kolonie”), where they were dedicated to protect these areas. In operation, the K-XVIII could host 38 crewmen (including 9 men from the Indies) that were well trained in diving and operations. The K-class was mainly used for patrolling the national waters of East Indies (Indonesia). The table shows some of it characteristics.

The K-XVIII would be the last of its class and of the dedicated submarines for the colonial waters. During the Second World War the K-XVIII defended the waters of the Dutch colony. On 24th of January 1942, after a battle with Japanese vessels, the K-XVIII was severely damaged by depth bombs and could not perform any diving maneuvers. It was escorted back by the aircraft carrier Y59 to Surabaya, were it needed repairs due to the damage. However, on 2nd of March 1942, the Dutch Navy decided to destroy the K-XVIII, because the repair services would not have been finished on time. The Japanese would reuse the hull of the K-XVIII as an air warning picket hull in 1944, but the British submarine H.M.S. TACITURN would eventually sink it on 16 July 1945.

Diving Procedure

The crewmembers aboard the K-XVIII performed diving procedures three times a day, on average. These procedures were performed by at least one third of the crew.

Diving procedures were performed on average three times a day during the expedition. During these procedures, Professor Vening Meinesz carried out his gravity measurements. The crew received a bonus when they fulfilled this task, so they were pleased the professor wanted to dive three times a day. They soon called his apparatus the “Golden Calf”.

All the valves in the submarine were checked under the command of Van der Linden, head of the engine room, before the diving procedure started. The mast and antenna at deck were taken down and strapped to the K-XVIII. Warrant officer Boskamp made sure the dinghy was secure and the shutters were closed. Most of the work however, was done in the control room at the centre of the submarine. The diesel engines were switched off and the main tanks were filled with water, which caused the submarine to submerge.

The rudders were set to zero just before the required depth was reached. To make sure the K-XVIII stayed at the same depth throughout the procedure, water could be moved between the different tanks. The professor started his measurements when the submarine was stabilized.

After forty minutes the procedure was reversed in order to ascend. The telegrapher listened if he heard the sound of a ship’s screw and one of the officers looked through the periscope to make sure there were no other ships in the neighbourhood. All the water was pumped out of the tanks and the diesel engines were turned on when the submarine had reached the surface. Finally, the shutters were opened and the deck was restored to the normal situation.

Spreading Ridge

The spreading ridge is an important aspect in plate tectonics. Vening Meinesz measured the gravity effect of several of these ridges during the voyage with the K-XVIII.

One of the secrets of the deep oceans is the spreading ridge. One of the most famous and longest ones is the Mid Atlantic Rise. It was discovered by the HMS Challenger and later mapped by other expeditions (e.g. Meteor1925-1927). The K-XVIII also sailed over this mysterious ridge, measuring the depth of the ocean floor and its gravity signal.

The crossing of the South Atlantic took 27 days, and Vening Meinesz acquired 51 observations of the gravity field. The voyage crossed several different submerged structures. From start of the voyage, a drop from the continental plateau can be seen, despite its absence in the gravity anomalies. This is because of the isostasy of continental plates. Then, the K18 crosses the Bromley Plateau, or Rio Grande Rise, as it is called today. Later in the voyage another submerged structure is observed, the Walvis Ridge. Both structures are remnants of hotspot volcanism. This structure is clearly seen as an anomaly in the gravity measurements. Then, an overall rise in both the gravity data and the bathymetry can be seen, with its magnitude at the center of the South Atlantic (around 2500 km in the crossing). The slightly positive anomalies indicate that there is no isostatic equilibrium.

Before these measurements, people believed that the deepest point of the oceans would be situated in the center of the ocean, just like in a lake or bathtub. However, the center of the ocean floor is a few km higher than at the floor at one quarter and at three quarter of the crossing. By inspecting the high-resolution depth measurements from the K-XVIII crew, Vening Meinesz deduced that this rise therefore should have a volcanic origin:

The soundings over the Mid Atlantic Rise showed an irregular topography, suggesting a volcanic landscape.

Vening Meinesz was able to deduce from his gravity measurements that this structure had a different nature than the volcanic arcs in West and East Indies. The characteristic negative anomaly was missing, which made Vening Meinesz conclude that the Mid Atlantic Rise was the result of another process.

It was actually Harry H. Hess (1906-1969), who explained the spreading ridge and became famous with his paper “History of Ocean Basins” (1962). These findings would eventually lead to the acceptance of plate tectonics thanks to the papers of Wilson (1965). Would Hess have been able to come up with his interpretation of the spreading ridge without his discussions with his close friend Vening Meinesz? It might be that the gravity measurements of the “fixist” Vening Meinesz made plate tectonics theory possible.

Tristan da Cunha

Tristan da Cunha is a volcanic island situated in the middle of the South Atlantic Ocean. On the island is a British settlement, which is one of the most remote places to live.

When the British government heard about the scheduled journey of the K-XVIII, they requested a minor detour. They asked the Royal Netherlands Navy to determine the economic situation on the island Tristan da Cunha in the Atlantic Ocean. The K-XVIII also brought mail and supplies to the island. The island is one of the most remote places in the world and ships visited it only once a year. The islanders had to survive until the next shipment by growing potatoes, keeping a limited supply of cattle, and fishing. They were a little bit shocked when the K-XVIIII arrived, because the Tristanians had never seen a submarine before. Their Reverend Harold Wilde was able to explain what it was.

Due to stormy weather, most of the crewmembers never set foot on the island. Vening Meinesz, Wytema and Hetterschij did visit and explained the citizens about their journey, the Netherlands and the submarine. Hetterschij concluded that the islanders had to be evacuated, because they could not cope with the rat- and insect-plagues that caused crop failures. The Tristanians became increasingly depended on passing ships and their supplies. Another problem was the poor health of these people. Many residents had respiratory problems. But in the end, the report did not lead to their evacuation and they were to stay on the island for several decades.

Hotspot Volcanism

Hotspot volcanism is one of the three types of volcanism found on Earth. The source for these volcanoes is found in the deep layers of the mantle.

There are three types of volcanism on Earth, where two types are related to plate tectonics: subduction volcanism and spreading ridge volcanism. The third type is more related to deep mantle effects, called hotspot volcanism. A typical case of hotspot volcanism is the volcano of Tristan da Cunha.

Hot material from the deep mantle is flowing upwards due to its increased buoyancy. When the material approaches the crust it tries to penetrate it, locally heating and melting the solid crust. Large basaltic plains all around the Earth are evidence of these eruptions. After the initial eruption a continuous flow of hot material extends volcanic eruptions. Volcanic island-trails are built, because a plate moves over the hotspot, producing a trail of dead volcanic structures like the Hawaiian Chain, or the Walvis Ridge.

Gravity compared

The incredible work is best shown when we compare the gravity observations of Vening Meinesz with current satellite data. Thanks to the incredible accurate observations of Vening Meinesz, numerous secrets of the Earth were discovered.

The gravity observations of Vening Meinesz have changed the way scientists look at the Earth, and his systematic way of working was an inspiration for future expeditions. One of the most remarkable aspects of the work of Vening Meinesz is the enormous devotion to the accuracy of the gravity measurements. Before he commenced the submarine voyages, Professor Vening Meinesz had performed numerous calibration experiments with his pendulum apparatus and his other equipment. Due to this tedious work, which took him several years, he was able to do measurements with a precision that is almost similar that of current satellite gravity missions.

Let’s compare the pendulum measurements with a gravity map solely based on satellite gravity mission, like NASA’s GRACE mission and ESA’s GOCE mission. The spatial resolution of Vening Meinesz’ measurements is of course much lower. He made about 240 measurements during this voyage, which is nothing compared to the thousand observations of satellites every week. To compare the gravity measurements done 80 years ago by Vening Meinesz, we can look at the crossing of the South Atlantic.

The top figure shows the free-air anomaly of the crossing of the South Atlantic. The observations of Vening Meinesz are in red and the satellite observations in black. Both the Rio Grande Rise (stations 620-623) and the Walvis Ridge (stations 640-644) are prominent features in the gravity signal. When we look at the absolute difference between Vening Meinesz’ measurements and the satellite measurements a mean difference of 10.6 mGal is seen with a standard deviation of 26.2. This is higher than the formal error estimate of the professor (max 8 mGal). The relative difference shows that most points are below 10 percent difference when compared to current satellite measurements. These observations are a remarkable achievement for a scientist on board a moving submarine some 80 years ago.

Stay at Cape Town

After a long and stormy stretch over the South Atlantic Ocean, the K-XVIII finally arrived in Cape Town. The crew and the professor were greatly welcomed.

On April the 1st, the K-XVIII arrived on the coast of Africa after a strenuous journey across the South Atlantic Ocean. The Dutch submarine received a warm welcome by the South Afrikaners. Due to maintenance on the submarine, the crew and Vening Meinesz stayed in Cape Town for several weeks. The professor, captain Hetterschij and several officers were invited for an automobile trip through the inlands of South Africa. This was an excellent opportunity to make several land-based gravity measurements with the Holweck-Lejay gravimeter. The profile obtained in the ocean could be extended on land, such that the professor could study continental isostasy.

The K-XVIII made a small trip to Simonstad after a week in Cape Town. Here in the large Navy docks, the submarine’s hull was cleaned after the 4 months journey. In the dry docks, workers would give the boat a new layer of paint after the hull had been scraped clean from small sea animals and rust. But before all this, Mr Searle, head engineer of the docks, challenged the fit submarine crew to compete against the dock personnel. The bay of Simonstad was full of fish and during the pumping of the dry dock; Mr. Searle knew many fish would get caught in the dock. Armed with brooms, both the submarine crew and dock personnel battled to catch the most fish. The dock personnel were very skilled, but lost against the enthusiasm of the submarine crew. As a consolation price the dockworkers received most of the fish to take home.

Pendulum Apparatus

Vening Meinesz had designed the pendulum apparatus in 1921 to remove vertical motions from the observations. This invention made it possible to observe the gravity field on the oceans.

The pendulum apparatus of Professor Vening Meinesz is also called “Het Gouden Kalf”, or The Golden Calf. This unofficial name was given by the numerous submarine crewmembers. For them this gravimeter meant extra income. To eliminate high-frequency motion during measurements, the submarine had to dive to 30 meters depth, where high-frequent wave-motion was damped. Furthermore, to reduce high-frequency oscillations, the crewmembers that were not needed to operate diving instruments, should lie in their bunks and remain still. Due to this decrease in personal freedom, they obtained extra payment every time an observation was made, making the pendulum apparatus a golden calf for the crewmembers.

The Golden Calf is an absolute gravimeter using the pendulum concept. Vening Meinesz designed this apparatus, which enabled him to remove external motion or disturbance from the measurement. This would later be very helpful in the submarine voyages.

By combining the motion of two pendulums, Vening Meinesz was able to eliminate the disturbing effect of motion of the submarine and other disturbances. Tiny mirrors attached to the pendulum reflect light beams. A photographic recording device on top of the measurement instrument records the moving light beams. With a clever design of several prisms, he was able to record a virtual pendulum. This virtual pendulum was not sensitive to the disturbing motion of the apparatus in the submarine.

His apparatus would be the only way to measure the gravity field with such high precision on the sea for the next 35 years. Eventually, it would be replaced by an Askania spring gravimeter on a stable platform, which could be used by surface ships.

Calibration and Time

The cause of his precise measurements of the gravity field is the numerous calibrations Vening Meinesz performed in the years before his expeditions.

The observations of Professor Vening Meinesz are extremely precise and thanks to this he could make many new scientific discoveries. He was able to measure the gravity field with this precision, due to his systematic and elaborate calibration efforts. Before the famous gravity expeditions at sea, the professor had spent many years calibrating and improving his measurement techniques. C.J. Wanders wrote about this in Memorial book for Vening Meinesz:

Het vraagstuk van de onrust van de bodem en zijn storende invloed op de bewegingen der slingers mag opgelost zijn, niet evenwel de onrust van de jeugdige geleerde, die ontelbare malen de treden van de oude instituutsingang oploopt en uren doorbrengt in de voor hem te lage kelderruimte. (C.J. Wanders)

Translation: The problem of the perturbed soil and its negative effect on the motion of the pendulums may have been solved, but the problem of the restless young scientist, who climbed the steps of the old institute building an infinite number of times and spent hours on end in a cramped basement, still remains. (C.J. Wanders)

For five whole years, he calibrated not only his pendulum apparatus, but also the chronometers. Temperature, humidity and pressure variations were tested and their effects on the instruments were documented. However, in those days no GPS or atomic time was yet available. So in order to obtain precise timekeeping, he asked for help of the Observatory of Delft and Leiden. Many letters between Vening Meinesz and the Observatory of Leiden were written in the period leading up to the expeditions.

The observatory of Delft, aiding Leiden, was responsible for Dutch time and had a Strasser-Rode clock located in the building for this purpose. This clock was the most accurate clock available in those times. Vening Meinesz spent many hours in the Observatory to calibrate his instruments. The professor would not be able to observe the Earth’s gravity field without these calibrations efforts.

Depth Measurements

The K-XVIII had sonar equipment on board for measuring the depth of the ocean floor, essential for Vening Meinesz’ studies. They revealed many secrets of the deep oceans.

In the old days, the depth of the ocean was measured by throwing a long rope overboard, for example Italian silk onboard the H.M.S. Challenger, with a heavy weight attached at the end. Techniques improve and the crew of the K18 had state-of-the-art equipment to measure the depth of the ocean more accurately. The Dutch Navy had installed the new “Atlas Echo Lood” device onboard the K18.

Sergeant C. Verstraten and Corporal A. Bauw were responsible for the depth measurements and worked closely together with the professor. To perform a measurement the operator had to send an acoustic signal into the water. After the transmission of this signal towards the ocean floor, a meter started to turn, which was visualized using a disc and a dial (see Figure for a sketch of this disc). The disc showed a range of 0-1000m with 100-meter increments. The operator then had to read the value on this meter after the acoustic signal was received again. The operators used headphones to listen for the return signal. Amplification of the signal was sometimes required for greater depths. The little engine, responsible for the rotation of the dial, was calibrated to convert the return time of the sounding signal into the correct depth. The device used a velocity of sound in seawater of 1500 m/s, so if the signal would return after two seconds, the ocean floor would be at a depth of 1500 meters. In the end, this device would allow a very accurate determination of the seafloor below the submarine. The precision of the Atlas Echo Lood was said to be within 20-30 meter.

Comité "Onze Marine"

The citizens of the Netherlands were excited by the long voyage of the K-XVIII. They started a comity to help the crew during the entire expedition.

Comité “Onze Marine” (committee “our Navy”) was established in 1921 to improve the relationship between the public and the Royal Netherlands Navy. The founder and chairman, A.W.P. Angenent, believed the journey of the K-XVIII would be the perfect opportunity to improve this relationship.

The committee notified newspapers about the expedition and ensured many articles were written. The committee members also collected money so they could send several shipments to the ports, where the K-XVIII visited. They send the normal supplies, but added nice gifts and letters as well. Angenent even arranged a broadcasting in Port Louis (Mauritius). The family members had gathered in the Netherlands to speak to their men over the radio. The crew members could hear their loved ones and many were touched to hear the voices of those they missed. In the meantime, the committee was already planning a next surprise. They created memorial stained glass windows. One was revealed in Surabaya at the arriving of the crew in July 1935; the other was revealed in Den Helder, where it remains until this day. In the end, the committee wrote a book about this journey with contributions of the crew, family members and other interested people. The committee wrote “Alles wel, geen bijzonders!!” to make sure this historical event would not be forgotten.

Troubles Onboard

In contrast with the reports from the movie and media, the mood onboard the K-XVIII wasn’t always excellent. There were some arguments between the professor and the captain.

Location Finding

To determine the position of the K-XVIII, the navigation officer would use a sextant to measure different angles between celestial objects.

On board any marine vessel it is crucial to estimate your location at any time. Of course, for the K-XVIII it was even more important, because the gravity observations would otherwise be useless. Therefore, officers of the submarine were constantly busy with determining their position. Back in those days, GPS positioning was not available, so they had to rely on less advanced techniques using astronomical objects in the sky. Navigating on the Sun and stars required the use of an instrument called a sextant. This device made it possible to measure the angles between certain stars or the angle between the horizon and the Sun. With these measurements and navigational maps, the crew of the K-XVIII was able to determine their position with an accuracy of a few minutes (2-3 km).

The sextant is used to measure the angles between stars at a certain time. The angle between the horizon and the Sun was measured at daytime. With these observations and an almanac, the navigation officer was able to determine the position of the K-XVIII. For example, to determine your latitude at night, you have to measure the angle between the “Pole star” and the horizon (this only works on the Northern Hemisphere). This angle is approximately equal to your latitude on the Earth because the viewing line is in the direction of the north celestial pole. The south celestial pole can be found in the vicinity of the Southern Cross.

Geoid Explained

Geodesy is the study that is responsible for measuring the shape of the Earth. One of their biggest concerns is the definition of 0 meter height, or sea level.

You have learned that the Earth is not a perfect sphere and that you can measure the curvature of the Earth by observing the gravity field. There is, however, more to learn about the structure of the Earth by observing the gravity field. One good example can be seen in the Indian Ocean, which Vening Meinesz and the K-XVIII crossed sailing from Mauritius to Fremantle, Australia. Unfortunately, the professor could not measure at all during the crossing, because extreme weather conditions made it impossible for the K-XVIII to perform diving maneuvers. Therefore, we look at gravity models constructed by satellite gravity missions.

In particular, we look at the geoid representation of the gravity field. The geoid is a surface where the gravity potential, or in other words the potential energy due to the gravitational field, remains constant. There are many of these surfaces, but the geoid is a special one, which is defined as 0 meters height, or sea level height. If there would be no winds and currents, the surface of all the water in Earth’s oceans would follow this geoid surface. We can see that the Earth is not a perfect ellipsoidal, but that it has dents (blue) and bulges (red). One of the largest dents is located in the Indian Ocean. Here, the ocean surface differs -110 meter from the ellipsoid. A maximum bulge is seen in Indonesia, where a high gravity potential results in an 80-meter rise of the ocean surface with respect to the ellipsoid. You would drop approximately 200 meters if you would sail with a boat from Indonesia to the center of the Indian Ocean, due purely to in homogeneities in the gravity field.

This difference in height was measured by the VPRO Beagle voyage in 2009-2010 with a GPS instrument. The results can be found here (link to website ).

Stay at Fremantle

Many Australians came to see the K-XVIII when it arrived in Fremantle. The professor visited the University of West Australia, where he made an observation of the gravity field.

The K-XVIII was the first submarine to visit the docks of Fremantle, which became an important submarine base in WWII. This gave Vening Meinesz the opportunity to visit the University of West Australia, of which a few records remain. One of them is a brass plaque that is mounted on the wall in the old building of the Department of Physics and Chemistry, now Occupied by Geology. Here, the gravity field was measured to be 979,390 mGal, or 9.79390 m/s^2. The stay in Fremantle and Perth was very valuable for Professor Vening Meinesz, as he states in “Gravity Expeditions at Sea Vol. III”:

In Fremantle we found a kind reception. The writer has especially to mention in this regard Dr. A. D. Ross, Professor of Physics at the University of W. Australia, who among other things arranged an extensive automobile trip for the making of Holweck-Lejay observations in the country. We went together as far as Merredin making observations at The Lakes, at York, at Quairading, at Bruce Rock, at Merredin and at Northam. Besides, the writer made a special series of observations in the new Physical Laboratory of Dr. Ross in Perth. As the reader will find exposed in volume IV of this publication where the discussion of the results is taken up, the results of these observations turned out to be of great importance. They have in themselves justified the taking along of the Holweck apparatus as well as the trouble taken for the observations.

Dr. Ross took the professor on a road trip through the inlands of West Australia, where several measurements of the gravity field were performed with the Holweck-Lejay gravimeter. These inland observations could subsequently be used to complete the coastal profile and study the continental isostasy.

Holweck-Lejay

The Golden Calf was too big and heavy to quickly take on land, so Vening Meinesz had acquired a Holweck-Lejay gravimeter from the “Bataafsche Petrolium Maatschappij” to perform land measurements.

During the voyage, Professor Vening Meinesz also had a smaller device with him to perform gravity measurements on land. The heavy pendulum apparatus was difficult to take out of the submarine and this was therefore only done during the stay at Cape Town. For land observations the Holweck-Lejay gravimeter was lent by the ‘Bataafse Petroleum Maatschappij’ (later merged to Shell), such that the professor was also able to observe the gravity field on land. This much smaller device, 15x15x30 cm in size, was much easier to take on land. The Holweck-Lejay gravimeter needed a very stable platform, like a concrete floor or some church steps as can be seen in the following clip.

The measurement principle of the Holweck-Lejay gravimeter was an oscillating inversed-pendulum in a vacuum chamber. From the period of the oscillating pendulum, Vening Meinesz was able to compute the local gravity field. For timing this period he took the Ullysses Nardin 17984 chronometer with him. After one hour, he would know the gravity with an accuracy of around 5 mGal.

The light source made it possible to observe the period (T) of the pendulum, which was measured with a chronometer. The value of the gravity could be obtained with the following relation:

The period is dependent on the spring constant, K, the mass of the pendulum, M, the length of the pendulum, L, the moment of inertia of the pendulum, I, and the gravity at the location, g. All these variables, except gravity, could be obtained in the laboratory beforehand, which made it possible for Vening Meinesz to observe the gravity all around the world.

Chronometers

Professor Vening Meinesz needed accurate timekeeping during his voyage for his precise gravity measurements, so he brought the best clocks available with him.

Timekeeping is very important for the navigation of a submarine. However, Vening Meinesz needed a more accurate timing for his gravity experiments. The period of his pendulums depends on gravity, so he wanted to observe the period as accurately as possible. The accuracy of his gravity anomalies depends on his ability in time keeping and should be the best possible. For this purpose, Vening Meinesz had brought four different chronometers onboard the K-XVIII.

• The Nardin 212
• The Nardin 2081
• The Brocking 1287
• The Ullysses Nardin 17984

The Nardin and Brocking chronometers were designed to give an electrical charge every half a second, which could be used by the Golden Calf. This charge briefly closes a shutter, which resulted in a small break in the recording. Due to these little breaks, it was possible to determine the period of the recorded signals with extreme precision. The three chronometers had a precision of a microsecond, or 1/1000 of a second. This was a remarkable feature in 1930.

The Nardin 212 is situated in the collection of the Depot TUDelft and is still in working order (see video link ). Due to its excellent performance, Vening Meinesz took the Nardin 212 on every one of his submarine expeditions.

The Nardin 2081 was the newest chronometer on board, but broke down during the voyage. The first time was at measurement 149, station 634. Then, it was somehow fixed, because it was used again for measurement 155. Finally, it broke down for the remainder of the voyage during measurement 211, station 696.

The Brocking 1287 was given by the French Navy to Vening Meinesz to be used during the K-XVIII expedition. Shortly before the K-XVIII expedition, Vening Meinesz had given the ‘Golden Calf’ with the Nardin chronometers to the French Navy to be used in their gravity expeditions. These exchanges of chronometers saved Vening Meinesz’ work, because the Nardin 2081 broke down at the end of the expedition, which would have consequences for the uncertainty estimate in the measurements.

The Ullysses Nardin 17984 was used for the Holweck-Lejay observations on Land. This small two-pointer stopwatch was easy to take on land excursions. The UN 17984 is seen in the movie, when Vening Meinesz is performing a Holweck-Lejay measurement on the steps of a small church (see Holweck-Lejay).

Subduction Zone

At the end of the journey of the K-XVIII they sailed over a subduction zone, which is, coincidentally, also the location of the end-of-life of an oceanic plate.

After leaving the port of Fremantle, the final part of the long voyage of the K-XVIII could commence. The K-XVIII would be enlisted in the service of the Dutch Navy to protect its colonies. The East Indies was a well-known area for the professor; here he came up with his theory on the famous Vening Meinesz belts. Unfortunately for Vening Meinesz, captain Hetterschij would not dive with the K-XVIII upon approaching the East Indies, because he wanted the submarine to look at its best. The whole vessel was cleaned and re-painted during the last few miles, before the K-XVIII entered the colonial waters. This made it impossible for Vening Meinesz to measure the subduction zone, south of Java. Luckily, on previous expeditions he had mapped this incredible feature in the gravity anomalies in detail.

A clear negative anomaly was observed parallel to the south islands of the East Indies. This negative anomaly had clear correlations with observed earthquakes and volcanoes on the islands. However, after isostatic reductions this negative anomaly was still present. This implied that the negative anomaly had nothing to do with the topography of that area, but that the cause originated in deeper layers of the Earth.

The characteristic observations for a subduction zone are earthquakes, a volcanic arc, an oceanic trench, and the gravity anomaly pattern observed by Vening Meinesz. The volcanism in the subduction zone is the result of the melting of oceanic sediments that are heated by the intense pressure and friction of the two plates. The ascending magma creates a volcanic arc along the subduction zone. The sliding of the two plates causes the earthquakes, which are known to be the biggest earthquakes on Earth. Oceanic trenches are the deepest points in the Earth oceans, which can go up to 11 km depth.

Reception at Surabaya

After eight months of sailing the oceans of the Earth, the K-XVIII with professor Vening Meinesz arrived at the final port, Surabaya, where a large crowd awaited them.

After eight months the K-XVIII and its crew arrived at their final destination, Surabaya, on 11 July 1935. The submarine had travelled over 23.000 miles and the crew had performed around 240 diving procedures so that Vening Meinesz could measure the gravity field.

Ships and airplanes welcomed the K-XVIII while the crew sailed into the port. The docks and ships were filled with people waving and cheering. Even some family members were present to celebrate this achievement with them. The men were brought to the Royal Netherlands Navy Submarine base for a festive ceremony. They were greeted by the vice admiral in the Dutch-Indies, submarine crews, family and friends. The vice admiral, Hetterschij and Van der Linden both gave a speech. They thanked the crew, the people they met at the ports and the gifts and interest of so many people, at home and abroad. Moreover, the K-XVIII was praised to be a well-made submarine. A conversation between the Minister for Defence Deckers and Hetterschij was broadcasted on the radio. Some of the men were honoured with royal decorations and all received a remembrance medal. Many speeches and gifts followed during the next few days, including the glass-stained window, arranged by the comity “Onze Marine”.

Wytema returned to the Netherlands just a few days after his arrival to edit his film, which premiered in 17th of January 1936 in the presence of Queen Wilhelmina and her daughter, Juliana. The journey of the K-XVIII continued to be popular: the expedition had been a great success.

Founder of NWO

Vening Meinesz was one of the founders of NWO. Thanks to his international network and experiences, the professor saw the possibilities of governmental funding in the scientific world.

Professor Vening Meinesz did not only conduct groundbreaking science, his organizational and innovative nature were also well represented. On one of his submarine voyages around the globe, Vening Meinesz visited universities in the USA. Here, he came into contact with a particular funding organization: the “Rockefeller Foundation”. This governmental-based funding-organization was responsible for funding many interesting research projects in the USA. Vening Meinesz recognized the possibilities of this kind of research funding and introduced the concept in the Netherlands. At first, his idea was not picked up, but in April of 1950 the Dutch government founded the ‘Stichting voor Zuiver Wetenschappelijk Onderzoek’. Vening Meinesz became a member of the Board of Directors. Later in 1988, ZWO became the now well-known NWO .

The mission of the Netherlands Organization for Scientific Research (NWO) has always been to improve the quality and innovative nature of scientific research as well was initiating and stimulating new developments. Thanks to the international visits and contacts of professor Vening Meinesz, this important institute was established and is now responsible for funding over a thousand Dutch research projects. The important contribution of Vening Meinesz to NWO is still seen in the Vening Meinesz award that NWO grants every two years to a remarkable Dutch scientist. The award was made possible, because of the donation of Vening Meinesz in 1962. The first winner of the award was Olaf Schuiling.