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Bogoslof Island
Bogoslof Island or Agasagook Island () is the summit of a submarine stratovolcano at the south edge of the Bering Sea, northwest of Unalaska Island of the Aleutian Islands chain. It has a land area of and is uninhabited. It is long and wide, with a peak elevation of . The stratovolcano rises about from the seabed, but the summit is the only part that projects above sea level. The island is believed to be relatively new, with the volcano being entirely below sea level before 1796, and most of the presently 300-acre island being formed by eruptions since 1900. History The first known emergence of the island above sea level was recorded during an underwater eruption in 1796. Since then, parts of the island have been successively added and eroded. About northwest of Bogoslof, a small volcanic dome emerged in 1883 from the same stratovolcano and has become a stack rock formation known as Fire Island (Aleutian Islands), Fire Island. On the southwest side of Bogoslof, another dome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States Geological Survey
The United States Geological Survey (USGS), founded as the Geological Survey, is an agency of the U.S. Department of the Interior whose work spans the disciplines of biology, geography, geology, and hydrology. The agency was founded on March 3, 1879, to study the landscape of the United States, its natural resources, and the natural hazards that threaten it. The agency also makes maps of planets and moons, based on data from U.S. space probes. The sole scientific agency of the U.S. Department of the Interior, USGS is a fact-finding research organization with no regulatory responsibility. It is headquartered in Reston, Virginia, with major offices near Lakewood, Colorado; at the Denver Federal Center; and in NASA Research Park in California. In 2009, it employed about 8,670 people. The current motto of the USGS, in use since August 1997, is "science for a changing world". The agency's previous slogan, adopted on its hundredth anniversary, was "Earth Science in the Pub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alaska Maritime National Wildlife Refuge
The Alaska Maritime National Wildlife Refuge (often shortened to Alaska Maritime or AMNWR) is a United States National Wildlife Refuge comprising 2,400 islands, headlands, rocks, islets, spires and reefs in Alaska, with a total area of , of which is wilderness. The refuge stretches from Cape Lisburne on the Chukchi Sea to the tip of the Aleutian Islands in the west and Forrester Island in the southern Alaska Panhandle region in the east. The refuge has diverse landforms and terrains, including tundra, rainforest, cliffs, volcanoes, beaches, lakes, and streams. Alaska Maritime National Wildlife Refuge is well known for its abundance of seabirds. About 75 percent of Alaskan native marine birds, 15 to 30 million among 55 species, use the refuge. AMNWR also provides a nesting habitat for an estimated 40 million seabirds, representing 80 percent of all seabirds in North America. The birds congregate in "bird cities" (colonies) along the coast. Each species has a specialized nesti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Volcanoes
An active volcano is a volcano that is currently erupting, or has the potential to erupt in the future. Conventionally it is applied to any that have erupted during the Holocene (the current geologic epoch that began approximately 11,700 years ago). A volcano that is not currently erupting but could erupt in the future is known as a dormant volcano. Volcanoes that will not erupt again are known as extinct volcanoes. Overview There are 1,350 potentially active volcanoes around the world, 500 of which have erupted in historical time. Many active volcanoes are located along the Pacific Rim, also known as the Pacific Ring of Fire. An estimated 500 million people live near active volcanoes. ''Historical time'' (or recorded history) is another timeframe for ''active''. The span of recorded history differs from region to region. In China and the Mediterranean, it reaches back nearly 3,000 years, but in the Pacific Northwest of the United States and Canada, it reaches back less tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Volcanoes In The United States Of America
This article contains a list of volcanoes in the United States and its territories. Alaska American Samoa Arizona California Colorado Hawaii Idaho Illinois Louisiana Michigan Mississippi Missouri Nevada New Hampshire New Jersey New Mexico North Carolina Northern Mariana Islands Oregon Texas Utah Virginia Washington Wyoming See also *Geothermal energy in the United States *List of Cascade volcanoes * List of large volume volcanic eruptions in the Basin and Range Province *List of volcanoes in Canada *List of volcanoes in Mexico *List of volcanoes in Russia *List of volcanic craters in Alaska * List of volcanic craters in Arizona * List of lava flows in Arizona *List of Yellowstone geothermal features * National Volcano Early Warning and Monitoring System * United States Geological Survey National Volcanic Threat Assessment References External links 2018 Update to the U.S. Geological Survey Nationa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of National Natural Landmarks
The National Natural Landmarks (NNL) Program recognizes and encourages the conservation of outstanding examples of the natural history of the United States. It is the only national natural areas program that identifies and recognizes the best examples of biological and geological features in both public and private ownership. The program was established on May 18, 1962, by United States Secretary of the Interior Stewart Udall. The program aims to encourage and support voluntary preservation of sites that illustrate the geological and ecological history of the United States. It also hopes to strengthen the public's appreciation of the country's natural heritage. As of July 2024, 605 sites have been added to the National Registry of Natural Landmarks. The registry includes nationally significant geological and ecological features in 48 states, American Samoa, Guam, Puerto Rico, and the U.S. Virgin Islands. The National Park Service administers the NNL Program and, if requested ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bogoslof Wilderness
Bogoslof Island or Agasagook Island () is the summit of a submarine stratovolcano at the south edge of the Bering Sea, northwest of Unalaska Island of the Aleutian Islands chain. It has a land area of and is uninhabited. It is long and wide, with a peak elevation of . The stratovolcano rises about from the seabed, but the summit is the only part that projects above sea level. The island is believed to be relatively new, with the volcano being entirely below sea level before 1796, and most of the presently 300-acre island being formed by eruptions since 1900. History The first known emergence of the island above sea level was recorded during an underwater eruption in 1796. Since then, parts of the island have been successively added and eroded. About northwest of Bogoslof, a small volcanic dome emerged in 1883 from the same stratovolcano and has become a stack rock formation known as Fire Island. On the southwest side of Bogoslof, another dome erupted in 1796; it is now call ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fur Seal
Fur seals are any of nine species of pinnipeds belonging to the subfamily Arctocephalinae in the family Otariidae. They are much more closely related to sea lions than Earless seal, true seals, and share with them external ears (Pinna (anatomy), pinnae), relatively long and muscular foreflippers, and the ability to walk on all fours. They are marked by their dense pelage, underfur, which made them a long-time object of commercial Seal hunting, hunting. Eight species belong to the genus ''Arctocephalus'' and are found primarily in the Southern Hemisphere, while a ninth species also sometimes called fur seal, the Northern fur seal (''Callorhinus ursinus''), belongs to a different genus and inhabits the North Pacific. The fur seals in ''Arctocephalus'' are more closely related to sea lions than they are to the Northern fur seal, but all three groups are more closely related to one another than they are to true seals. Taxonomy Fur seals and sea lions make up the family Otariidae. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Overcast
Overcast or overcast weather, as defined by the World Meteorological Organization, is the meteorological condition of clouds obscuring at least 95% of the sky. However, the total cloud cover must not be entirely due to obscuring phenomena near the surface, such as fog. Overcast, written as "OVC" in the METAR observation, is reported when the cloud cover is observed to equal eight oktas (eighths). An overcast sky may be explicitly identified as thin (mostly transparent), but otherwise considered opaque—which always constitutes a ceiling in aviation meteorology. Sometimes clouds can be of different colors such as black or white, but overcast usually refers to darker skies.''Oxford English Dictionary'', 3rd ed. (website), s.v. “overcast," 2a and 2b. http://www.oed.com/view/Entry/134377#eid32922408 (Accessed September 7, 2016). In some cases, it can be characterized by almost zero distinction of borders of clouds. Or the sky may be covered by a single type of cloud, such as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dirty Thunderstorm
Volcanic lightning is an electrical discharge caused by a volcanic eruption rather than from an ordinary thunderstorm. Volcanic lightning arises from colliding, fragmenting particles of volcanic ash (and sometimes ice), which generate static electricity within the volcanic plume, leading to the name dirty thunderstorm. Moist convection currents and ice formation also drive the eruption plume dynamics and can trigger volcanic lightning. Unlike ordinary thunderstorms, volcanic lightning can also occur when there are no ice crystals in the ash cloud. The earliest recorded observations of volcanic lightning are from Pliny the Younger, describing the eruption of Mount Vesuvius in 79 AD, "There was a most intense darkness rendered more appalling by the fitful gleam of torches at intervals obscured by the transient blaze of lightning." The first studies of volcanic lightning were also conducted at Mount Vesuvius by Luigi Palmieri who observed the eruptions of 1858, 1861, 1868, and 18 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Ash Cloud
Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, produced during volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used to refer to all explosive eruption products (correctly referred to as ''tephra''), including particles larger than 2 mm. Volcanic ash is formed during explosive volcanic eruptions when dissolved gases in magma expand and escape violently into the atmosphere. The force of the gases shatters the magma and propels it into the atmosphere where it solidifies into fragments of volcanic rock and glass. Ash is also produced when magma comes into contact with water during phreatomagmatic eruptions, causing the water to explosively flash to steam leading to shattering of magma. Once in the air, ash is transported by wind up to thousands of kilometres away. Due to its wide dispersal, ash can have a number of impacts on society, including animal and hum ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Eruption
A volcanic eruption occurs when material is expelled from a volcanic vent or fissure. Several types of volcanic eruptions have been distinguished by volcanologists. These are often named after famous volcanoes where that type of behavior has been observed. Some volcanoes may exhibit only one characteristic type of eruption during a period of activity, while others may display an entire sequence of types all in one eruptive series. There are three main types of volcanic eruptions. Magmatic eruptions involve the decompression of gas within magma that propels it forward. Phreatic eruptions are driven by the superheating of steam due to the close proximity of magma. This type exhibits no magmatic release, instead causing the granulation of existing rock. Phreatomagmatic eruptions are driven by the direct interaction of magma and water, as opposed to phreatic eruptions, where no fresh magma reaches the surface. Within these broad eruptive types are several subtypes. The we ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boiling Mud Pot On Bogoslof Island By Nora Rojek USFWS
Boiling or ebullition is the rapid phase transition from liquid to gas or vapour; the reverse of boiling is condensation. Boiling occurs when a liquid is heated to its boiling point, so that the vapour pressure of the liquid is equal to the pressure exerted on the liquid by the surrounding atmosphere. Boiling and evaporation are the two main forms of liquid vapourization. There are two main types of boiling: nucleate boiling, where small bubbles of vapour form at discrete points; and critical heat flux boiling, where the boiling surface is heated above a certain critical temperature and a film of vapour forms on the surface. Transition boiling is an intermediate, unstable form of boiling with elements of both types. The boiling point of water is 100 °C or 212 °F but is lower with the decreased atmospheric pressure found at higher altitudes. Boiling water is used as a method of making it potable by killing microbes and viruses that may be present. The sensitivity of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
