Earthquake-related anomalies recorded by two borehole bulk-strain meters

Abstract

: This paper gives a report on borehole bulk-strain data recorded at the seismostations of Liuhe and Nantong in Jiangsu Province from January 1, 2003 to December 31, 2008. While the data at Nantong showed much noise possibly due to site instability and no earthquake-related changes, the data at Liuhe showed anomalous changes that began one to several weeks before three earthquakes of magnitude 4.0 to 6.0 at epicentral distances up to 400 km.

Keywords

• borehole bulk strain
• atmospheric pressure
• rainfall
• disturbance
• short-term and impending abnormality