报告题目: Geodetic observations of thawing permafrost
Accumulating observation evidence shows widespread thawing and degradation of permafrost, or ground remains frozen perennially, both in the Arctic and on the Qinghai-Tibetan Plateau. Thawing permafrost has profound effects on terrestrial ecosystems, on hydrologic and landscape processes, and on human infrastructure. A large amount of carbon currently frozen in permafrost may release into the atmosphere and further warms the global climate. However, it is challenging to study and monitor permafrost, which is purely defined by its subsurface thermal condition. In this talk, I will present the innovative use of two geodetic methods: space-borne radar interferometry and GNSS Reflectometry, to study permafrost degradation in Northern Alaska and gain quantitative understandings on seasonal, decadal, gradual, as well as abrupt changes in ice-rich permafrost.
Lin Liu is an assistant professor of Earth System Science at the Chinese University of Hong Kong. He studied at Wuhan University for his bachelor degree and got his PhD in Geophysics from the University of Colorado. Before joining CUHK, he was a George Thompson Postdoc Fellow at the Stanford University. His study applies a wide range of geodetic, geophysical, and remote sensing techniques to the Earth’s complex cryospheric systems including permafrost and glaciers, aiming to quantify and understand their significant changes in a warming climate.