Details

Autor(en) / Beteiligte

• Tanaka, Yusuke
• Ohta, Yusaku
• Miyazaki, Shin'ichi

Titel

Real‐Time Coseismic Slip Estimation via the GNSS Carrier Phase to Fault Slip Approach: A Case Study of the 2016 Kumamoto Earthquake

Ist Teil von

• Geophysical research letters, 2019-02, Vol.46 (3), p.1367-1374

Ort / Verlag

Washington: John Wiley & Sons, Inc

Erscheinungsjahr

2019

Quelle

Wiley Online Library

Beschreibungen/Notizen

• We investigate the feasibility of Global Navigation Satellite System (GNSS)‐based deformation monitoring that detects coseismic fault slip directly from GNSS carrier phases without conventional positioning analysis. This method, which we call the phase‐to‐slip (PTS) method, does not require high‐quality orbital information because it relies only on changes in azimuthal site‐to‐satellite ranges. With this method, computational costs for real‐time seismic monitoring can be reduced. Here we applied the PTS method to the mainshock of the 2016 Kumamoto earthquake by modifying the original algorithm and using both precise orbits by International GNSS Service (IGS) and broadcast orbits. In both cases, obtained coseismic slip distributions agree well with previous studies. Calculated surface displacements from inferred slip distributions also agree with traditional positioning analysis. These results suggests that the PTS method may be useful as a supplement to currently operated deformation monitoring system, especially when external orbit and clock information are not accessible. Plain Language Summary Earthquake monitoring and tsunami forecasting are both of great importance in active earthquake areas, such as Japan. However, monitoring ground movements during or immediately after an earthquake is difficult and requires great computational effort using current methods. Our study explores the possibility of using a relatively low effort method of monitoring ground movement using simple Global Positioning System information available for an array of satellites. While this method, originally developed by Cervelli and colleagues in 2002, is still in need of improvement to generate more stable estimates over long periods of time, it shows great promise as an additional tool that may ultimately improve our ability to predict earthquake‐induced hazards, including tsunami. Key Points The phase‐to‐slip method of coseismic fault slip monitoring is effective for short time series using precise and rough orbital data Real‐time earthquake monitoring can be improved by the use of phase‐to‐slip estimates as redundant systems with low computational costs Earthquake monitoring and tsunami forecasting in interplate areas could benefit from incorporating phase‐to‐slip estimates