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Atmospheric Parametric Spatiotemporal Characteristics of the 2008 Wenchuan, 2010 Yushu, 2013 Lushan and 2017 Jiuzhaigou Earthquakes, in the Eastern Margin of Bayan Har Block and Discussion on Genesis and Prediction of Continental Earthquakes

Session: Application of Remote Sensing and Space-Based Earth Observations Data in Earthquake Research II

Type: Oral

Date: 4/22/2021

Presentation Time: 05:30 PM Pacific

Description: 

Since 2008, Wenchuan, Yushu, Lushan and Jiuzhaigou strong earthquakes happened in in the eastern margin of Bayan Har block, in the northeastern Tibetan Plateau. Whether the strong tectonic activities of the four earthquakes are regular or not, and whether there is genetic relationship among them, is of great significance for understanding intra-continental plate earthquakes and developing continental prediction with new ideas.

In this study, CH4 was taken as medium - and long-term observation factor, and RST algorithm was used to extract abnormal information. Combined with atmospheric parameters (SKT, OLR, TCWV, O3 and SLHF), the tide force was considered to analyses short-impending anomaly information.

Our results shows that CH4 can be used as a well precursor of seismic activeity. The anomaly appears 1- 4 months before the main earthquake, and the closer to the epicenter, the larger the amount of emitted gas. The peak values were found at intersection areas. The CH4 anomaly appeared about 1 month before Wenchuan EQ,about 2 month before Lushan EQ, about 3 month before Yushu EQ and about 4 month before Jiuzhaigou EQ. It may be that the activity of Bayan Har block has increased since the Wenchuan earthquake. The cumulative number of earthquakes in the study area can prove that. The similarity of time sequence of the other anomalies between that atmospheric parameters may be related to the same process. The evolution of these parameters in time and space goes through the process of micro enhancement-enhancement-micro attenuation-enhancement-calmness, which was consistent with the process of micro rupture - rupture - locking - Accelerated rupture - rupture experienced by rock stress strain – rupture. The observed anomalies maybe as the consequence of the upraising of gases from a fluid-rich middle/upper crust along pre-existing seismogenic faults, and of their release into the atmosphere. It also shows that in the practice of earthquake prediction our method used in this paper will help to improve the earthquake prediction ability.

Presenting Author: Jing Cui

Student Presenter: No

Authors