空间大地测量技术在火山形变监测中的应用

岩浆活动的不同阶段引起地表变化不同。地表形变受压力源大小、形状、深度及岩浆运移速率等影响;另外火山类型不同,地形不同,形变特征也不同。地表形变幅度范围很大,为1×10-7—1米量级。火山区形变监测可以了解火山活动状态,有助于进行喷发危险性的预测预报。形变监测从20世纪60年代的传统技术逐渐过渡到20世纪90年代发展起来的GNSS和InSAR等大地测量新技术,火山区形变时空监测能力得到提高,同时缩短了预测时间。我国火山形变监测开始较晚,现已在长白山天池、腾冲以及海南等主要火山区开展监测。传统的连续测量以地倾斜观测为主;新技术主要以流动GNSS监测为主,连续观测站少,InSAR技术研究时间密度不够;目前形变监测还不能实现很好的时空覆盖。

Application of Geodesy Technology in Deformation Monitoring of Volcanoes

The surface deformation varies with magmatic activities in different periods. Deformation monitoring can help to understand the activities and to evaluate the potential risk of eruption. Generally, the deformation in volcano area is affected by the magamatic source pressure, size, shape, depth and migration rate and etc. The volcanic types also can cause different deformation on the surface. The range of amplitude is from 1×10^-7 to 1 meter-scale. The new geodetic technologies developed in the 1990s, such as GNSS and InSAR, gradually replaced the traditional technique of the 1960s. The monitoring capability has been improved in temporal-spatial domain. The deformation monitoring of active volcanoes in China started late in 1990s, which has been used in the volcano monitoring of Tianchi Changbaishan, Tengchong and Hainan volcanoes. However, the continuous deformation measurement is done only with tilting. The application of new geodesy technologies, such as continuous GNSS, is not enough in these volcano regions.