Determination of optimal gravity mission for the coseismic earthquake signals detection

Document Type: Original Article

Author

Department of Surveying Engineering, Marand Technical College, University of Tabriz, Tabriz, Iran

Abstract

The gravity field of the earth has temporal variations and our instruments are unfortunately defective and imperfect to measure that. Therefore, our knowledge of the gravity field of the earth is not complete. After launching satellite gravity missions, gravity data has been collected with a remarkable quality. One of the changes that takes place under the surface of the earth is a mass movement, which occurs as a result of several earthquakes. In the case of using multiple satellites, we might be able to achieve an additional amplification of the gravity signal through inter-satellite tracking between two low orbits. In this paper, five scenarios were simulated and compared with one another. For a better comparison, five different simulated faults in three deferent positions were considered to the orbit simulation scenarios. We also used the simulated data of both the earthquake and orbit propagation scenarios. In addition, we added normal noises in satellites orbit propagation step. Then, the 1964 earthquake caused by the Alaska () fault was investigated as a case study. For the Alaska fault, the seawater effect was considered, as well. The results indicated that the observations made by Helix and Pendulum scenarios had a better susceptibility to earthquake signals, and GRACE and GRACE-FO had the least susceptibility. Therefore, the radial track is considered to be an important part of observations as well as cross-track and along-track to be in the next order, respectively.

Keywords