Transcontinental tidal transect: European Atlantic coast-Southern Siberia-Russian Pacific coast

Abstract

The paper presents results of measurements with digital tidal LaCoste-Romberg gravimeters on the European Atlantic coast-Southern Siberia-Russian Pacific coast transect in 1995–2005. The transect includes four West European (Chize, Menesplet, Mordelles, and Wikle), two South Siberian (Klyuchi and Talaya), and two Far Eastern (Zabakalskoe and Yuzhno-Sakhalinsk) stations. Gravimetric measurements at the Talaya station (SW Baikal rift zone) are supplemented by long-term laser extensometer observations. The position of the stations within the rectangle (45°–55°N, 0.4°–142°E) allows one to assess existing tidal strain models (WD93 and DDW99) and various ocean tide models (SCW80, CSR3, FES95, ORI96, CSR4, FES02, GOT00, NAO99, and TPX06). Data of intracontinental stations (with a small ocean effect at distances of 2000–3000 km) agree well with the DDW99 tidal strain model (with regard to the mantle viscosity). The uncertainty of digital tidal gravity measurements is 0.25%. Results of laser extensometer measurements are at the same accuracy level. Then, the Love and Shida numbers calculated at midlatitudes of the intracontinental zone of Eurasia from combined data are h = 0.6077 ± 0.0008, k = 0.3014 ± 0.0001, and l = 0.0839 ± 0.0001. The analysis of results of Pacific and Atlantic stations located at distances of 30–300 km from the ocean showed that the FES02, CSR4, GOT00, NAO99, and TPX06 ocean tide models are preferable.