Print Email Facebook Twitter Observing coseismic gravity change from the Japan Tohoku-Oki 2011 earthquake with GOCE gravity gradiometry Title Observing coseismic gravity change from the Japan Tohoku-Oki 2011 earthquake with GOCE gravity gradiometry Author Fuchs, M.J. Bouman, J. Broerse, D.B.T. Visser, P.N.A.M. Vermeersen, L.L.A. Faculty Civil Engineering and Geosciences Department Geoscience & Remote Sensing Date 2013-10-17 Abstract The Japan Tohoku-Oki earthquake (9.0 Mw) of 11 March 2011 has left signatures in the Earth's gravity field that are detectable by data of the Gravity field Recovery and Climate Experiment (GRACE) mission. Because the European Space Agency's (ESA) satellite gravity mission Gravity field and steady-state Ocean Circulation Explorer (GOCE)—launched in 2009—aims at high spatial resolution, its measurements could complement the GRACE information on coseismic gravity changes, although time-variable gravity was not foreseen as goal of the GOCE mission. We modeled the coseismic earthquake geoid signal and converted this signal to vertical gravity gradients at GOCE satellite altitude. We combined the single gradient observations in a novel way reducing the noise level, required to detect the coseismic gravity change, subtracted a global gravity model, and applied tailored outlier detection to the resulting gradient residuals. Furthermore, the measured gradients were along-track filtered using different gradient bandwidths where in the space domain Gaussian smoothing has been applied. One-year periods before and after earthquake occurrence have been compared with the modeled gradients. The comparison reveals that the earthquake signal is well above the accuracy of the vertical gravity gradients at orbital height. Moreover, the obtained signal from GOCE shows a 1.3 times higher amplitude compared with the modeled signal. Besides the statistical significance of the obtained signal, it has a high spatial correlation of ~0.7 with the forward modeled signal. We conclude therefore that the coseismic gravity change of the Japan Tohoku-Oki earthquake left a statistically significant signal in the GOCE measured gravity gradients. Subject GOCEgravity gradientsJapan Tohoku-Oki earthquakecoseismic gravity change To reference this document use: http://resolver.tudelft.nl/uuid:755ecbfc-742f-4737-a5a3-ddc8f8ababb5 DOI https://doi.org/10.1002/jgrb.50381 Publisher American Geophysical Union Embargo date 2014-04-17 ISSN 0148-0227 Source Journal of Geophysical Research: Solid Earth, 118 (10), 2013 Part of collection Institutional Repository Document type journal article Rights © 2013 American Geophysical Union Files PDF Broerse_2013.pdf 2.3 MB Close viewer /islandora/object/uuid:755ecbfc-742f-4737-a5a3-ddc8f8ababb5/datastream/OBJ/view