Walter Zürn: Paul Melchior Medalist for 2021

Walter Zürn receives the Paul Melchior Medal during the 19th International Symposium on Geodynamics and Earth Tides which is held in the week of June 22nd 2021 in Wuhan (China) and online (due to the Covid-19 pandemic). With this medal ‘outstanding scientists with a huge experience and influence in the Tidal Community are awarded’ about every four years. Walter Zürn is a member of the Geophysical Institute (GPI) since 1974 and still active in scientific research after his retirement in 2002. In his early career he operated an Earth tide gravimeter at the geographical South Pole (Amundsen-Scott South Pole Station) at a location where the Earth is exposed to long period tides only. Diurnal and semidiurnal signals there are predominantly due to ocean loading and allow a specific investigation of this phenomenon. During his time at Black Forest Observatory (BFO) Walter Zürn challenged the international community with measurements of exceptional quality made with the LaCoste Earth Tide gravimeter ET-19, which pushed the further development of superconducting gravimeters. Dedicated experiments which Walter Zürn carried out at BFO, established the acceptance of so called cavity-effects which are caused by strain-tilt coupling due to local heterogeneity. This helped in the interpretation of recordings of tidal tilt and strain, which predominantly are sensitive to local properties of the crust. Many more of Walter Zürns achievements are  mentioned in the Laudatio which is published on the conference web-site. We congratulate Walter Zürn warmly to this well-deserved award.

The Black Forest Observatory (BFO).