Tectonic geomorphology on regional and global scales: an old methodology upon new technologies

• 作 者: Yasutaka IKEDA
• 机 构: Department of Earth and Planetary Science, University of Tokyo, Japan
• 出 处: 干旱半干旱环境对地观测国际会议
• 发表日期: 2012年7期
• 关键词: Tectonic landforms Active faults Air-photo interpretation Stereoscopic satellite

Tectonic-geomorphological methods are effective in studying crustal deformation in recent geologic time,which gives a link between ongoing tectonic processes and orogenesis.Recent GPS observations have made it possible to detect crustal strain precisely and extensively,but are not sufficient in time to cover a whole cycle of strain buildup and release in orogenic belts.GPS-derived strain includes both elastic and inelastic components.An extensive elastic-strain buildup,if existed,would eventually result in a large strain-release event on a plate-boundary or deep-seated fault zone (e.g.,the 2011 Tohoku earthquake of Mw 9.0).From the viewpoint of earthquake forecasting,we need to extract elastic strain from GPS-derived strain data.The elastic component of crustal strain can only be measured by evaluating the inelastic (= permanent) strain buildup on a geologically long time scale,because the elastic strain buildup and release are cyclic and hence cancelled/averaged out each other over a long period of time.