11/6/2022 0 Comments Zenonia 1 gold hex editorThis new finding indicates that a close relationship existed between polar motion and climate change in the past. The accelerated terrestrial water storage decline resulting from glacial ice melting is thus the main driver of the rapid polar drift toward the east after the 1990s. Only the latter scenario, along with the atmosphere, oceans, and solid Earth, agrees with the polar motion during the period of 1981–2020. The second scenario assumes that it changed from observed glacier ice melting. One scenario assumes that the terrestrial water storage change throughout the entire study period (1981–2020) is similar to that observed recently (2002–2020). This study introduces a novel approach to quantify the contribution from changes in terrestrial water storage by comparing its drift path under two different scenarios. However, short-term observational records of key information in the hydrosphere (i.e., changes in terrestrial water storage) limit a better understanding of new polar drift in the 1990s. Generally, polar motion is caused by changes in the hydrosphere, atmosphere, oceans, or solid Earth. The Earth's pole, the point where the Earth's rotational axis intersects its crust in the Northern Hemisphere, drifted in a new eastward direction in the 1990s, as observed by space geodetic observations. The developed high accuracy topography map will expand the possibility of geoscience applications that require high accuracy elevation data such as terrain landscape analysis, flood inundation modelling, soil erosion analysis, and wetland carbon cycle studies. Here detected height errors were larger than actual topography variability, and following error removal landscapes features such as river networks and hill-valley structures at last became clearly represented. Significant improvements were found, especially in flat regions such as river floodplains. After error removal, global land areas mapped with ☒m or better accuracy increased from 39% to 58%. The height errors included in the original DEMs were separated from actual topography signals and removed using a combination of multiple satellite datasets and filtering techniques. Here we developed a new high accuracy map of global terrain elevations at 3" resolution (~90m at the equator) by eliminating multiple error components from existing spaceborne DEMs. While very precise Digital Elevation Models (DEMs) based on airborne measurements are available in developed regions of the world, most areas of the globe rely on spaceborne DEMs which still include non-negligible height errors for geoscience applications. Terrain elevation maps are fundamental input data for many geoscience studies. We conclude that future work analyzing measurements of crustal motion (across various fields in Earth science) should correct for the deformation associated with modern ice-mass loss at sites distant from melting ice. This 3-D surface motion is on average several tenths of a millimeter per year, and it varies significantly year-to-year. We show that, rather than only being localized to regions of ice loss, melting of the Greenland Ice Sheet and Arctic glaciers has caused significant horizontal and vertical deformation of the crust that extends over much of the Northern Hemisphere. In this study, we use satellite-derived constraints on early 21st century ice-mass balance of the Greenland and Antarctic Ice Sheets and a global database of mountain glaciers and ice caps, to predict how the crust has deformed over the last two decades. As ice sheets and glaciers melt and water is redistributed to the global oceans, the Earth's crust deforms, generating a complex pattern of 3-D motions at Earth's surface.
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