Atmospheric Responses to Pre-earthquake Processes Revealed by Satellite and In-situ Observations. Case Study for XinJiang, China (2008-2014)

Abstract:

We are presenting the latest development in multi-sensor observations of short-term pre-earthquake phenomena preceding major earthquakes. The purpose of this study is to verify if satellite thermal infrared radiation (OLR) anomalous signals can be found retrospectively in association with three major earthquakes in XinJiang province China (M6.9 of 02.12.14; M6.2 of 08.12.2012 ; M7.2 of 03.20.08) by systematically applying analysis of multi-sensor satellite thermal and ground temperature/humidity observations for the period of 2008-2014. Meteorological satellite data include NOAA polar orbit NPOES and Chinese geostationary satelliteFY2D. In-situ atmospheric data include NOAA data recorded near the Hotan (37°N 80°E) weather station.

In the case of M6.9 of 02.12.14 NOAA-18 OLR survey for January –February shows that the initial indication of building an atmospheric anomaly was detected in the period 20-30 of January (10-20 days before the main shock) and maximum reached on Jan 21 westward from the epicenter. The OLR reference field was built for the entire period of 2004-2014. FY2D OLR data show similar trend in detecting OLR signals by revealing anomalous value with persistency of more then 9 hours on Jan 31, 2014. The 2012 (M 6.2) and 2008 (M7.2) event shows similar OLR anomalies (the 2012 events has the smallest value) that were building near to the epicenter area, over the major Altyn Tagh fault lines within 10-15 days before the seismic event. This probably is connected with the gas release enhancement and additional flux emission and provides information about major fault activation in this area. The hourly in-situ observation show similarly in the air temperature increases for (strong for 2008 and 2014, weak for 2012) and the relative humidity drops, probably as the result of additional atmospheric ionization as observed before the three earthquake events.

Our initial results suggest that systematic use of multi-parameters and multisensory observation of pre-earthquake anomalies, provides some additional tools for validation of the observed physical parameters associated with earthquake processes.