Influence of the Earth’s Local Structure on Elastic Surface Deformations Caused by Atmospheric, Hydrologic, and Oceanic Loads

Abstract:

The deformational response of the Earth to atmospheric surface pressure, water-storage loads, and ocean bottom pressure on seasonal or shorter time scales is usually represented by a set of elastic load Love numbers or alternatively the corresponding Green's function spectrum. As these response functions are determined for one radial Earth structure like PREM, they are not appropriate for small-scale surface loads, less than 2500km², that probe the heterogeneous shallow crustal structure of the Earth. Typical small-scale mass load features occur along the major river channels and the ocean coastline.

In order to consider variations in the Earth structure, we derive local Green's functions for each 1°x1° grid cell of the 3D crustal structure model CRUST1 and applied them to high-resolution atmospheric, hydrologic, and oceanic surface loads. We will discuss the sensitivity of the calculated load deformations to changes in the Earth structure.