Determination of Land-Surface Deformation of Northern Taiwan by Using Persistent Scatterers InSAR 

Fong-Min Chou

Abstract

The Tatun volcano group of northern Taiwan is formed by extensional collapse, which started after the collision between the Luzon volcanic arc and Eurasian continental margin at about 5 Ma.In the 1990s, both the Unzen volcano of Kyushu in Japan and the PinatuboMountain of the middle LuzonIsland erupted. Therefore, whether the Tatun volcano group would erupt, like Unzen and PinatuboMountain, has become an important issue to people living in Taipei basin.

The northwest part of Taipei basin is covered by lahar originated from Tatun volcano group and its thickness reaches over eighty meters in the very northwest corner of the basin.If the distribution of the population and building in Taipei basin stay in a similar pattern, it would cause inconceivable casualty and damage to property if the volcano erupted.

We set out to investigate the surface deformation of Tatun volcano group between 2003 and 2007 using the archived radar images acquired by Envisat satellite that was launched by ESA.We plan to use Persistent Scatterers Interferometric Sythetic Aperture Radar (PSInSAR) to extract the deformation signal. Since the region of Tatun volcano group is covered with varying vegetations over different seasons, therefore the noise of DInSAR interferograms are often too high to see surface deformation.The atmospheric disturbance can be reduced by using PSInSAR, so that we can acquire the information of crustal deformation effectively.Aside from natural PS, we erected man-made corner reflectors in our study area of Tatun volcano group.These corner reflectors will appear in radar image as apparent spots, which could be easily recognized and regarded as surface control points.

Reference

Alessandro Ferretti, Claudio Prati, and Fabio Rocca, Nonlinear subsidence rate estimation using permanent scatterers in differential SAR interferometry, IEEE transactions on geoscience and remote sensing, vol.38, no.5, September 2000

(Abstract) (Full text)

Hooper, A., Segall, P., Zebker, H., and kampes, B., A new method for measuring deformation on volcanoes and other natural terrains using InSAR persistent scatterers, Geophysical Research Letters, Vol.31, L23411, doi:10.1029/2004GL021737, 2004.

(Abstract) (Full text)