Exploration of Prompt Elastogravity Signal for the 2004 M9.0 Sumatra and 2010 M8.8 Maule Earthquakes

Xinyu Jiang, & Lingsen Meng

Published August 15, 2018, SCEC Contribution #8695, 2018 SCEC Annual Meeting Poster #087

A rapid detection is of great importance to earthquake and tsunamis early warning. Generated by the change of gravitational field, instantaneous signals which travels at the speed of light and are much faster than elastic waves such as P wave, have a potential for quick detection and accurate size estimation of earthquake events. However, researchers haven’t taken wide use of them because of the small magnitude of these signals and lack of big earthquakes with short durations. With the data of 2011 Mw 9.0 Tohoku earthquake, progress has recently been made in statistical (Montagner et al. 2016) or observational (Vallée et al. 2017) studies. But there are still not many observations of other events because of the noise and incomplete coverage of stations. Here we show our exploration to detect the gravity perturbation signal between event time and P arrival time for the 2004 Mw 9.0 Sumatra earthquake and the 2010 Mw 8.8 Maule earthquake. We apply methods previously used in the Tohoku earthquakes to the broadband seismograms of the Sumatra and Maule earthquake. Seismic array analysis is also included to boost the signal to noise ratios of station clusters. For the Sumatra earthquake, there exists an obvious trend using simple stacking of waveforms recorded by the XF array in Tibet. The statistical significance of a signal before P arrival, which exceeds the background noise, is more than 97%. While limited by the data quality of the Maule earthquake, the observation of the gravity signal is not certain given the strong background noise. In the future work, we plan to adopt more advanced seismic array processing to improve the signal-to-noise ratio of the prompt gravity signal and try to provide a theoretical value for comparison.

Key Words
gravity signal

Citation
Jiang, X., & Meng, L. (2018, 08). Exploration of Prompt Elastogravity Signal for the 2004 M9.0 Sumatra and 2010 M8.8 Maule Earthquakes. Poster Presentation at 2018 SCEC Annual Meeting.

Related Projects & Working Groups
Seismology