Broadband Downhole Seismic Array at Guandu Nature Park, Taipei City

operated by IES in November, 2006

In 2004, the Institute of Earth Sciences (IES) of Academia Sinica was contracted by the Central Geological Survey (CGS) of the Ministry of Economic Affairs to initiate a four year project ofuGeophysical investigation and monitoring for micro-earthquake in metropolitan Taipeiv. The purpose of this project is to investigate, evaluate and continuously monitor the seismic activities of the faults and low frequency tremors in the Taipei area. The IES was given the responsibility for setting up a portable broadband seismic network covering the Taipei areat in 2004 and continued in the process of more site selections to install stations from 2005 to 2007. Because the Taipei Basin is a densely urbanized area with wide diffusion of roads and railway traffic, industries and agricultural activities the high cultural noise produced by these activities represents a serious problem which affects seismic observations. Therefore, three permanent broadband downhole seismic stations were also established to avoid noise on the alluvium plain in this project. Installation of these three stations was completed in 2005 at Daan Park (DANB), 2006 at Guandu Nature Park (GDUB) and 2007 at Hsinchung Life Hall Park (SNJB). This is our first experience installing and operating broadband downhole seismic stations in Taipei Basin.

Station GDUB is located in the Guandu Nature Park, is at the northern end of the potential fault of Shanchiao. The Park is a place of Migrating Birds marsh area and situated in northern Taiwan at the point of convergence of Danshui and Keelung Rivers.