Inner Crater
Encyclopedia
Inner Crater is the topographic feature that embraces the crater within the floor of Main Crater
, q.v., at the summit of Mount Erebus
, Ross Island
. Inner Crater contains an active anorthoclase
-phonolite
lava lake
. The name is derived from the fact that the crater is within the Main Crater of Mount Erebus.
Main Crater
Main Crater is the topographic feature that rises to c.3750 m and forms the primary summit crater of Mount Erebus on Ross Island. Inner Crater, q.v., which lies within Main Crater, contains an anorthoclase-phonolite lava lake....
, q.v., at the summit of Mount Erebus
Mount Erebus
Mount Erebus in Antarctica is the southernmost historically active volcano on Earth, the second highest volcano in Antarctica , and the 6th highest ultra mountain on an island. With a summit elevation of , it is located on Ross Island, which is also home to three inactive volcanoes, notably Mount...
, Ross Island
Ross Island
Ross Island is an island formed by four volcanoes in the Ross Sea near the continent of Antarctica, off the coast of Victoria Land in McMurdo Sound.-Geography:...
. Inner Crater contains an active anorthoclase
Anorthoclase
The mineral anorthoclase is a crystalline solid solution in the alkali feldspar series, in which the sodium-aluminium silicate member exists in larger proportion. It typically consists of between 10 and 36 percent of KAlSi3O8 and between 64 and 90 percent of NaAlSi3O8....
-phonolite
Phonolite
Phonolite is a rare igneous, volcanic rock of intermediate composition, with aphanitic to porphyritic texture....
lava lake
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...
. The name is derived from the fact that the crater is within the Main Crater of Mount Erebus.