Initial scalar lithospheric magnetic anomaly map of China and surrounding regions derived from CSES satellite data

Abstract

The China Seismo-Electromagnetic Satellite (CSES), China's first satellite to measure geophysical fields with scientific goals in both space and solid earth physics, was launched successfully in February 2018. It carries high-precision magnetometers to measure the geomagnetic field. In this study, the CSES magnetic data were used to extract the signal of the lithospheric magnetic field caused by magnetized rocks in the crust and uppermost mantle. First, an along-track analysis of the CSES magnetic data was undertaken near the Bangui magnetic anomaly in central Africa and the Tarim magnetic anomaly in China, demonstrating that the CSES magnetic data are indeed sensitive to the lithospheric magnetic anomaly field. Then a lithospheric magnetic anomaly map over China and surrounding regions was derived. This map is consistent with the lithospheric part of the CHAOS-7 model. In particular, it clearly reveals four major magnetic anomalies containing long-wavelength signals at the altitude of lowearth-orbiting satellites. Three magnetic highs are located over the Tarim, Sichuan and Songliao basin, the origins of which could be related to large-scale tectonic-magmatic activities during geological history. A prominent magnetic low is otherwise found in the southern Himalayan-Tibetan plateau, possibly caused by the shallow Curie depth in this region. To further improve the precision of the lithospheric magnetic field model, more detailed data processing and multi-source data merging are needed.

Seismic assessment of high-rise buildings through dynamic nonlinear analysis

“…Based on international standards [Wang et al, 2021a], the numerical values of ground surface acceleration (𝛾)…”

An Improved In-Flight Calibration Scheme for CSES Magnetic Field Data

“…2023, 15, 4578 2 of 11 work together to provide magnetic field measurements from DC to ~15 Hz. Previous scientific studies have shown very good usability of the magnetometer data [7][8][9]. In-flight calibration based on the CDSM's scalar data is in principle well established and the quality is already very good.…”

Preliminary geological interpretation of long-wavelength magnetic anomalies over China and surrounding regions

“…Data from the ESA's Swarm satellite constellation (2013−), which comprises three identical satellites (Friis-Christensen et al, 2006), has facilitated creation of various high-quality lithospheric field models (Thébault et al, 2016;Olsen et al, 2017). The CSES (China Seismo-Electromagnetic Satellite, 2018-) is designed to facilitate earthquake studies and to measure geophysical fields, supporting scientific goals of both space and solid earth physics (Shen XH et al, 2018;Huang JP et al, 2018); its scalar magnetic data have been used for lithospheric magnetic anomaly identification and modeling (Wang J et al, 2021(Wang J et al, , 2023a. In May 2023, a new Chinese satellite aiming at monitoring geomagnetic changes, the Macao Science 1 satellite (Zhang K K, 2023), was launched.…”

“…Compared to the more striking magnetic anomalies around the world, the long-wavelength magnetic anomalies in China and surrounding regions are much weaker, with maximum amplitudes of about 5 nT at 500 km altitude (Figure 2). Thanks to high-resolution magnetic measurements and mature modeling methods, many researchers have begun to notice these magnetic anomalies and have done general analyses using geological and tectonic data (An ZC et al, 1992;Zhang CD, 2003;Kang GF et al, 2010;Ou JM et al, 2013;Du JS, 2014;Gao GM et al, 2018;Wang J et al, 2020aWang J et al, , 2023a. However, specialized research on these weaker anomalies has been quite inadequate to clarify their geological origins or to facilitate further tectonic applications.…”