High Resolution Gravity Images Using ERS-1 Satellite Altimetry - a New Aid to Oil Exploration

Various satellite altimetry Exact Repeat Missions (Seasat, Geosat, ERS- 1, Topex/Poseidon) have measured sea surface heights over the globe, along a series of co-linear repeat tracks. These give oceanographic as well as geophysical information on scales down to about 75 km. Over the past year the ERS-1 satellite has been in a Geodetic Mission, where there are no repeats, but a dense pattern of tracks has been built up, with 8km track sparing at the Equator, decreasing with latitude (figure 1): These data, which extend to 81.5 degrees latitude (north and south) provide a much higher spatial resolution than has previously been available and give gravity models down to 10km resolution (figure 2).