A caldera is not the lapp thing as a volcanic crater. Craters are formed by the outbound explosion of rock south and other materials from a vent. Calderas are formed by the inbound collapse of a volcano. Craters are normally more circular than calderas. ( Calderas may have parts of their sides missing because domain collapses unevenly. ) Craters are besides normally much smaller than calderas, entirely extending to a utmost of one kilometer ( less than a mile ) in diameter.
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Types of Calderas
Crater Lake, in the U.S. state of Oregon, is in a crater-lake caldera, not a crater. The Crater Lake caldera is about 10 kilometers ( 6 miles ) across-the-board. Crater Lake is the deepest lake in the United States. It resulted from an volcanic eruption that occurred more than 7,000 years ago at the ancient Mount Mazama. The bang wholly emptied Mount Mazama ’ s magma chamber. The magma bedroom ’ randomness roof then collapsed and filled with urine from rain and snow, creating the lake. subsequent eruptions of Mount Mazama built up Wizard Island, a volcanic cone that forms an island on the westerly end of the lake .
Deception Island, located off the seashore of Antarctica, is another crater-lake caldera. Unlike Mount Mazama, the Deception vent is still active. The Deception vent experienced a violent bang roughly 10,000 years ago that caused its summit to collapse and flood with seawater, forming a caldera about 7 kilometers ( 4.4 miles ) wide-eyed. The caldera gives the island its unique horseshoe shape, which opens to the sea through a narrow channel. Deception Island ’ s alone geological structure makes it one of the only places in the worldly concern where vessel randomness can sail directly into an active vent
Shield Volcano Calderas
Composed of dormant and active shield volcanoes, the islands of Hawaii have a count of impressive shield vent calderas. Moku’aweoweo, the caldera at the summit of Mauna Loa on the “ Big Island ” of Hawaii, is actually comprised of three distinct depressions that lap. In sum, the caldera complex has an area of approximately 15 square kilometers ( 6 square miles ) and reaches a depth of 180 meters ( 600 feet ) .
The Galápagos Islands are besides a series of shield volcanoes with some acme calderas. Fernandina Island, the most volcanically active voice island in the chain, has a deep elliptic caldera that measures 4-by 6.5-kilometers ( 2.5-by 4-miles ). In 1968, a massive volcanic bang produced one of the largest caldera collapses in holocene history. Like most shield volcano calderas, Fernandina caldera collapsed incremental ly and asymmetrical ally, sinking in adenine much as 350 meters ( 1,150 feet ) in some parts .
Resurgent caldera s are the largest volcanic structures on Earth, ranging from 15 to 100 kilometers (9 to 62 miles) in diameter. They are not associated with one particular volcano, but instead result from the widespread collapse of vast magma chambers. This caldera collapse is produced by incredibly destructive eruptions known as pyroclastic sheet flows, the likes of which have not occurred in historic times.
The Toba Caldera on the indonesian island of Sumatra is the newest resurgent caldera, created roughly 74,000 years ago by the largest volcanic eruption in the last 25 million years. This massive outbreak eject ed 2,800 cubic kilometers ( 1,740 cubic miles ) of debris. The volcanic eruption left a caldera 100 kilometers ( 62 miles ) long, 29 kilometers ( 18 miles ) wide-eyed, and 508 meters ( 1,666 feet ) deep, making it the largest volcanic structure on Earth. The caldera is now home to Lake Toba and Samosir Island. Samosir was formed by the uplift of the caldera deck due to magma pressure below. This uplift is common to all resurgent calderas as new magma fills in the empty magma chamber over thousands of years .
The Yellowstone Caldera, located in Yellowstone National Park in the U.S. state of Wyoming, is the result of the Yellowstone Supervolcano. This enormous vent complex last erupted about 640,000 years ago. The yellowstone Caldera is more than 72 kilometers ( 45 miles ) long. recent scientific analyses have revealed that the caldera ’ s magma chamber is 2.5 times larger than previously thought, measuring an incredible 90 kilometers by 30 kilometers ( 55 miles by 20 miles ) and 10 kilometers ( 6 nautical mile ) deep. These raw measurements put the magma bedroom at roughly the same size it was during its end eruption .