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METEORITE IMPACT STRUCTURES ON EARTH
Impact structures on Earth are classified as either simple or
complex structures. Simple impact structures measure up to four
kilometers in diameter and contain uplifted and overturned rim
rocks which surround a classic bowl-shaped depression. Complex
impact structures, also called basins, are more than four kilometers
in diameter. The center of the complex structure is uplifted,
forming a central peak, and the rim and crater walls are slumped.
Large-diameter craters often display one or more peak rings, rather
than a single central peak.
To date, scientists have identified approximately 150 visible
impact craters across the globe. While most of the Earth’s
craters were recognized as geologic features before 1950, it was
only since the mid 1960s that the meteorite-impact origins began
to be recognized. Technological advances in spacecraft orbital
imagery have been tremendous aids in identifying several new craters,
especially in remote locations.
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