Ice velocity mapping of Ross Ice Shelf, Antarctica by matching surface undulations measured by ICESat laser altimetry

REMOTE SENSING OF ENVIRONMENT

卷:124

Article

Lee, Choon-Ki¹  Seo, Ki-Weon¹  Han, Shin-Chan^2,3  Yu, Jaehyung⁴  Scambos, Ted A.⁵ 

[1] Korea Polar Res Inst, Div Polar Earth Syst Sci, Inchon, South Korea

[2] NASA, Goddard Space Flight Ctr, Planetary Geodynam Lab, Greenbelt, MD 20771 USA

[3] Univ Maryland Baltimore Cty, Joint Ctr Earth Syst Technol, Baltimore, MD 21228 USA

[4] Chungnam Natl Univ, Dept Geol & Earth Environm Sci, Taejon, South Korea

[5] Univ Colorado, CIRES, Natl Snow & Ice Data Ctr, Boulder, CO 80309 USA

关键词: Ice velocity;    Laser altimetry;    Ross Ice Shelf;   

DOI  :  10.1016/j.rse.2012.05.017

来源: Elsevier

【 摘 要 】

We present a novel method for estimating the surface horizontal velocity on ice shelves using laser altimetry data from the Ice Cloud and land Elevation Satellite (ICESat; 2003-2009). The method matches undulations measured at crossover points between successive campaigns. Elevation measurements are first relocated into a time-varying (moving) coordinate system using an initial velocity (e.g., from VELMAP), and then crossover height differences are minimized with an adjustment vector. Errors in geolocation of the ICESat tracks result in some error in the adjustment vectors, but these are small relative to the velocity adjustment for fast-moving ice shelves. We use the algorithm to estimate changes in the ice velocity of Ross Ice Shelf between an earlier mapping (from VELMAP) and the ICESat period. The new velocity field is compared with velocities from in situ measurements and satellite radar interferometry. The slowdown of 98 +/- 34 m yr(-1) (similar to 23%) is observed in the ice shelf downstream of Whillans Ice Stream, and the deceleration rate is 3.1 +/- 1.1 m yr(-2) during last three decades. The method can be expanded to the simultaneous mapping of ice horizontal velocity, ice thickness change, and surface deformation for Antarctic ice shelves as well as a more accurate mapping using future ICESat-2 measurements. (c) 2012 Elsevier Inc. All rights reserved.

【 授权许可】

Free