Useful satellite data concerning sea ice began in late 1978 with the launch of NASA's Scanning Multichannel Microwave Radiometer (SMMR) satellite.
Answer:
Coastal landforms are often subtle or are difficult to distinguish from other features, such as stratigraphic terraces and fault scarps, and often extend over vast areas, requiring both high-resolution imaging and regional coverage.
Hello friend,
if i am not wrong crust is believed to generate its magnetic field..
hope that helps u
