Earthquake Remote Sensing Frontier Research

BACKGROUND

On January 17, 1995, the city of Kobe, Japan was struck by a large earthquake. Beginning in 1996 in response to "Earthquake Integrated Frontier Research" project of the Science and Technology Agency (STA), NASDA decided to conduct the "Earthquake Remote Sensing Frontier Research" (ERSFR) project. This project is composed of two research projects. One is application of SAR interferometry to earthquake monitoring and prediction and the other is observation of seismo-electromagnetic and other related phenomena of earthquakes.

APPLICATION OF THE SAR INTERFEROMETRY TECHNIQUE

In 1978, SEASAT (JPL/U. S. Navy) which was the first satellite to have a synthetic aperture radar (SAR) was launched and acquired lots of new information. Repeat-pass SEASAT/SAR imagery were interferometry processed and topographic information of land and sea surface was generated. Until Massonet et al. succeeded in interferometry processing of SAR imagery of the deformation caused by the Landers earthquake from ERS-1/AMI data (published in 'Nature', 1993, p. 138-142) SAR imagery was not used for land deformation studies. After that several real-time interferometry satellite systems have been proposed at JPL and Tsukuba Space Center. Also in Japan, NASDA and Geographical Survey Institute succeeded in interferometry processing and produced an image of the surface deformation caused by the Kobe earthquake from JERS-1/SAR data. NASDA is planning the following studies in SAR interferometry application in the ERSFR project.

Satellite and airborne SAR experiments
Automatic processing study of interferometry imagery
Validation method study between topographic data of interferometry imagery and measured data by DEM and GPS.
Correction method study to remove bias error by atmospheric vapor

Moreover, as a future satellite project, we are planning to study the possibility of international cooperation.

SEISMIC ELECTROMAGNETIC RESEARCH

Electric and magnetic signal anomalies occurring before an earthquake are well known. Researchers in Greece have used the VAN method for earthquake prediction. However, VAN measures only direct current on the ground. The LF background noise increases with the seismic electromagnetic precursor, reported first by Gokhberg et al. in 1982. Since that time, several satellite projects have been proposed in France, Russia and Ukraine to observe seismic electromagnetic precursors. NASDA is planning following studies in seismic electromagnetic anomaly observation in the ERSFR project.

Correlation analysis between plasma anomaly satellite data and earthquakes
Correlation analysis between VLF signal of Omega navigation system and earthquakes
Detection on anomalous behaviors of plasma (+ high energy plasma) associated with earthquakes
Detection method study of seismo- electromagnetic source by using three components observation of electric and magnetic field (direction finding)
Ionosphere 3D tomography analysis by domestic GPS array data of the Geophysical Survey Institute
Schumann resonance study as an indicator of the global warming
Mission requirement for the satellite observation

Moreover, as a future satellite project, we are planning to study the possibility of international cooperation.

RESEARCH FRAMEWORK

Principle scientist who has a unique concept of the research controls the budget and manpower for the project. NASDA promotes the research work by this frontier research framework.
The research work is performed at the Earth Observation Research Center (EORC) and project researcher is entrusted as a NASDA invited researcher.
The period of the research project is basically 5 years.
The ERSFR project of NASDA is associated with the ' Earthquake International Frontier Research ' project led by Dr. Seiya UYEDA of the Institute of Physical and Chemical Research ( RIKEN ) which performs ground observation of seismo electromagnetic precursors.

PROJECT MEMBERS

Principle Scientist:: Prof. Naoyuki FUJII *; Prof. Masashi HAYAKAWA **
Invited Researcher:: Dr. Oleg Alexandrovich MOLCHANOV; Dr. Yasuhide HOUBARA; Dr. Takako SAKURAI; Dr. Shigeki KOBAYASHI
NASDA Researcher:: Dr. Masanobu SHIMADA *
Support Staff:: Ken-ichi NOMURA