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The diameter of the original crater is uncertain, but has been estimated to be from 30 to 70 km (19 to 43 mi). [2] Computer simulations of a 7 km (4.3 mi) in diameter impactor crashing into a 2 km (1.2 mi) thick ice sheet covering granite bedrock produced a crater of final diameter compatible with the Yarrabubba crater. [1]
The eruptions began with a 6 km (4 mi)-long fissure-based "curtain of fire" on 3 January 1983. These gave way to centralized eruptions on the site of Kilauea's east rift, eventually building up the cone. [4] For a list of all of the volcanoes of Hawaii, see List of volcanoes in the Hawaiian – Emperor seamount chain. Mount Etna, Italy. [4]
A central-peak crater is the most basic form of complex crater. A central-peak crater can have a tightly spaced, ring-like arrangement of peaks, thus be a peak ring crater, though the peak is often single. [3] Central-peak craters can occur in impact craters via meteorites. An Earthly example is Mistastin crater, in Canada. [1]
Although sometimes described as a crater, the feature is actually a type of sinkhole, as it is formed through subsidence and collapse rather than an explosion or impact. Compared to the thousands of volcanic eruptions that occur over the course of a century, the formation of a caldera is a rare event, occurring only a few times within a given ...
The landscape has since been eroded to a depth of around 7–11 km (4.3–6.8 mi) since formation, obliterating the original crater. The remaining structure, the "Vredefort Dome", consists of a partial ring of hills 70 km (43 mi) in diameter, and is the remains of the central uplift created by the rebound of rock below the impact site after the ...
The cantilever model describes the formation of the lopoliths as a result of the tilting of floor about a point at the pluton margin. [4] It deforms the underlying crust by simple shear and leads to the sinkage of partial melt. [4] In the piston model, the formation of lopolith begins when the central block floor sinks. [4]
Tuff rings have a low profile apron of tephra surrounding a wide crater (called a maar crater) that is generally lower than the surrounding topography. The tephra is often unaltered and thinly bedded, and is generally considered to be an ignimbrite , or the product of a pyroclastic density current.
Crater morphology provides information about the physical structure and composition of the surface. Impact craters allow us to look deep below the surface and into Mars geological past. Lobate ejecta blankets (pictured left) and central pit craters are common on Mars but uncommon on the Moon , which may indicate the presence of near-surface ...