Wondering about polar wander

Recently the 7500th research data set has been uploaded to the 4TU.ResearchData archive. This a significant milestone in ensuring the accessibility of technical scientific research and sharing knowledge. The data team provide services to support researchers in making their data available for reuse.They were curious about what the research behind this data set was all about and went to find out at the Faculty of Aerospace Engineering.

Displacement of mass

hr_mks9853Haiyang Hu is one of the researchers behind the data. “We have been researching polar wander and worked on a method to more accurately predict this phenomenon. The North and South Poles of the Earth are slowly moving. This takes place on many planets or moons and is referred to as polar wander. It is caused by the movement of materials on and in the planet. The displacement of the mass changes the moment of inertia of the planet. Therefore the poles are constantly shifting.”

“Polar wander can be the explanation for why we find surface features at certain locations. For instance, enceladuswe often observe huge mountains near the equator of a planet or moon, ,or deeper oceans near the poles. This is usually the consequence of polar wander: these mountains could have formed anywhere on the planetary body, but due to the polar wander, they eventually end up on the equator. This is the case for the Tharsis plateau near the equator of Mars and for the so-called ‘tiger stripes’ near the pole on icy moon Enceladus.”


Accurate predictions

“The mathematical description of polar wander on planetary bodies is difficult, and only approximated solutions have been obtained in the past. Our study establishes a new method which can give an accurate prediction of how the polar wander proceeds through time. We show that previous studies have incorrectly estimated the speed of polar wander on Mars and Venus. With the new method, polar wander on a wide range of planetary bodies can be simulated. The speed of polar wander will be higher on a planet with lower viscosity. A planet or moon deforms much easier in such a case. The predictions of our method can be compared to actual surface features, which will give us a better understanding what a planet or moon is made of. “

Sharing the data and program is part of our scientific integrity

When asked about his scientific drive: “I like solving problems. A solution for a complex issue gives me a great sense of achievement. We spent a lot of hours on both the research, and on developing a software program for our calculations. We decided to share both the data and the program, because it is not only about the data, but also how you generate them. That is part of our scientific integrity. I believe in the Open Science movement. The publication establishes that it is our achievement. The software is linked to the data. If it then saves others time and leads to do more research, I am happy to share.”hr_mks9869

Haiyang Hu

Library information box

Looking for a place to store your unique research output for years to come and boost your visibility? 4TU.Centre for Research Data is here to facilitate your needs: 4TU.Centre for ResearchData (short 4TU.ResearchData) offers researchers a reliable long-term archive for technical and scientific research data. It creates opportunities for linking publications to underlying data thereby promoting improved findability and citability for research data.
4TU.Centre for Research Data

More information

Haiyang Hu – Faculty of Aerospace Engineering H.Hu-1@tudelft.nl
Link to data: “A full-Maxwell approach for large angle polar wander of viscoelastic bodies” https://doi.org/10.4121/uuid:7a932119-cf0e-4710-b2f7-2655b2befa4b

Author: Marieke Hopley – TU Delft Library m.j.hopley@tudelft.nl

Photography: Marcel Krijger – marcel@marcelkrijger.nl
Photo of Enceladus by NASA

Don’t want to miss the next edition? Subscribe here!

TU Delft Library