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Lava Lake
Lava lakes are large volumes of molten lava, usually basaltic, contained in a volcanic vent, crater, or broad depression. The term is used to describe both lava lakes that are wholly or partly molten and those that are solidified (sometimes referred to as ''frozen lava lakes''). Formation Lava lakes can form in three ways: *from one or more vents in a crater that erupts enough lava to partially fill the crater; or *when lava pours into a crater or broad depression and partially fills the crater; or *atop a new vent that erupts lava continuously for a period of several weeks or more and slowly builds a crater progressively higher than the surrounding ground. Behaviors Lava lakes occur in a variety of volcanic systems, ranging from the basaltic Erta Ale lake in Ethiopia and the basaltic andesite volcano of Villarrica, Chile, to the unique phonolitic lava lake at Mt. Erebus, Antarctica. Lava lakes have been observed to exhibit a range of behaviours. A "constantly circu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Volcanic Crater Lake
A volcanic crater lake is a lake in a volcanic crater, crater that was formed by explosive eruption, explosive activity or a caldera, collapse during a types of volcanic eruptions, volcanic eruption. Formation Lakes in calderas fill large craters formed by the collapse of a volcano during an eruption. Lakes in maars fill medium-sized craters where an eruption deposited debris around a vent. Crater lakes form as the created depression, within the Rim (craters), crater rim, is filled by water. The water may come from Precipitation (meteorology), precipitation, groundwater circulation (often Hot Spring, hydrothermal fluids in the case of volcanic craters) or melted ice. Its level rises until an equilibrium is reached between the rates of incoming and outgoing water. Sources of water loss singly or together may include evaporation, subsurface seepage, and, in places, surface leakage or overflow when the lake level reaches the lowest point on its rim. At such a saddle location, the u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Kīlauea
Kīlauea ( , ) is an active shield volcano in the Hawaiian Islands. It is located along the southeastern shore of Hawaii (island), Hawaii Island. The volcano is between 210,000 and 280,000 years old and grew above sea level about 100,000 years ago. Since the islands were settled, it has been the most volcano#Active, active of the Hawaii (island)#Volcanism, five volcanoes that together form the island and among the most active volcanoes on Earth. The most recent eruption began in December 2024, with episodic lava fountains and flows continuing into 2025. Kīlauea is the second-youngest product of the Hawaiian hotspot and the current eruptive center of the Hawaiian–Emperor seamount chain. Because it lacks topographic prominence and its activities historically coincided with those of Mauna Loa, Kīlauea was once thought to be a satellite of its much larger neighbor. Kīlauea has a large, fairly recently formed caldera at its summit and two active rift zones, one extending east ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Mount Nyiragongo
Mount Nyiragongo ( ) is an active stratovolcano with an elevation of in the Virunga Mountains associated with the Albertine Rift. It is located inside Virunga National Park, in the Democratic Republic of the Congo, about north of the town of Goma and Lake Kivu and just west of the border with Rwanda. The main crater is about wide and usually contains a lava lake. The crater presently has two distinct cooled lava benches within the crater walls – one at about and a lower one at about . Nyiragongo's lava lake has at times been the most voluminous known lava lake in recent history. The depth of the lava lake varies considerably. A maximum elevation of the lava lake was recorded at about prior to the January 1977 eruption – a lake depth of about . Following the January 2002 eruption, the lava lake was recorded at a low of about , or below the rim. The level has gradually risen since then. Nyiragongo and nearby Nyamuragira are together responsible for 40% of Africa's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
South Sandwich Islands
The South Sandwich Islands () are a chain of uninhabited volcanic islands in the South Atlantic Ocean. They are administered as part of the British Overseas Territory of South Georgia and the South Sandwich Islands. The chain lies in the sub-Antarctic region, about southeast of South Georgia and northeast from the tip of the Antarctic Peninsula. The archipelago comprises 11 main islands forming an island arc running north–south, the largest being Montagu at . It is divided into four groups, from north to south: The Traversay, Candlemas and Central Islands ( Saunders, Montagu, and Bristol), and Southern Thule. The archipelago is prone to violent earthquakes. Over the previous century, nine M 7+ earthquakes have occurred here, the most recent being the M 8.1 in August 2021. None of these earthquakes are known to have caused fatalities due to their remote location. History The southern eight islands of the South Sandwich Islands were discovered by Captain ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Saunders Island, South Sandwich Islands
Saunders Island is a crescent-shaped island lying between Candlemas Island and Montagu Island in the South Sandwich Islands, a British Overseas Territory in the southern Atlantic Ocean. The long Saunders is a volcanic island composed of an active stratovolcano, Mount Michael, and a cluster of pyroclastic cones on the southeastern side. Mount Michael has a lava lake in its summit crater, which is fumarolically active, and there is widespread evidence of recent eruptions across the island. The island is used as a breeding ground by many bird species, including penguins, but is barren of vegetation apart from lichens and some moss-covered patches. Most of the island is covered in ice. Geography and geology Regional Saunders Island was discovered in 1775 by James Cook from , and is part of the South Sandwich Islands in the southern Atlantic Ocean at the eastern end of the Scotia Sea. They lie about north of Antarctica and about the same distance south-east of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Mount Michael
Mount Michael is an active volcano with a height of 843 m. It is located on Saunders Island in the South Sandwich Islands, a British Overseas Territory in the southern Atlantic Ocean. It is one of the few volcanoes in an overseas territory of the United Kingdom. The volcano was discovered by a British expedition under James Cook in 1775, but was presumably first charted in 1820 by a Russian expedition under Fabian Gottlieb von Bellingshausen. It was recharted in 1930 by DI personnel under Commander W.M. Carey of the Royal Navy, who was captain of the '' Discovery II'' at the time of the survey. Persistent lava lake In 2019, it was discovered that Mount Michael had a persistent lava lake, a rare phenomenon which is known to occur at only eight volcanoes in the world. In November 2022, an expedition from University College London led by geologist A geologist is a scientist who studies the structure, composition, and History of Earth, history of Earth. Geologists incorporate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Masaya Volcano
Masaya () is a caldera located in Masaya (department), Masaya, Nicaragua, south of the capital Managua. It is Nicaragua's first and largest national park, and one of 78 protected areas of Nicaragua. The complex volcano is composed of a nested set of calderas and volcanic crater, craters, the largest of which is Las Sierras shield volcano and caldera. Within this caldera lies a sub-vent, which is Masaya Volcano ''wikt:sensu stricto, sensu stricto''. The vent is a shield volcano, shield type composed of basaltic lavas and tephras and includes a volcanic crater, summit crater. This hosts Masaya caldera, formed 2,500 years ago by an basaltic ignimbrite eruption. Inside this caldera a new basaltic complex has grown from eruptions mainly on a semi-circular set of vents that include the Masaya and Nindiri cones. The latter host the pit craters of Masaya, Santiago, Nindiri and San Pedro. Observations in the walls of the pit craters indicate that there have been several episodes of c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Hawaii
Hawaii ( ; ) is an island U.S. state, state of the United States, in the Pacific Ocean about southwest of the U.S. mainland. One of the two Non-contiguous United States, non-contiguous U.S. states (along with Alaska), it is the only state not on the North American mainland, the only state that is an archipelago, and the only state in the tropics. Hawaii consists of 137 volcanic islands that comprise almost the entire Hawaiian Islands, Hawaiian archipelago (the exception, which is outside the state, is Midway Atoll). Spanning , the state is Physical geography, physiographically and Ethnology, ethnologically part of the Polynesian subregion of Oceania. Hawaii's ocean coastline is consequently the List of U.S. states and territories by coastline, fourth-longest in the U.S., at about . The eight main islands, from northwest to southeast, are Niihau, Niihau, Kauai, Kauai, Oahu, Oahu, Molokai, Molokai, Lanai, Lānai, Kahoʻolawe, Kahoolawe, Maui, and Hawaii (island), Hawaii, a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Hawaii (island)
Hawaii is the List of islands of the United States by area, largest island in the United States, located in the Hawaii, state of Hawaii, the southernmost state in the union. It is the southeasternmost of the Hawaiian Islands, a chain of volcanic islands in the Pacific Ocean, North Pacific Ocean. With an area of , it has 63% of the Hawaiian archipelago's combined landmass. However, it has only 13% of the archipelago's population. The island of Hawaii is the third largest island in Polynesia, behind the North Island, North and South Islands of New Zealand. The island is often referred to as the Island of Hawaii or Hawaii Island to distinguish it from the state. It is also referred to as The Big Island, due to its size relative to the other islands. In Hawaiian language, Hawaiian, the island is sometimes called ''Moku o Keawe''. The word ''keawe'' has several meanings. One definition, "southern cross", is said to be the name of an ancient chief. Another definition is "the bearer". ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Ross Island
Ross Island is an island in Antarctica lying on the east side of McMurdo Sound and extending from Cape Bird in the north to Cape Armitage in the south, and a similar distance from Cape Royds in the west to Cape Crozier in the east. The island is entirely volcanic. Mount Erebus, , near the center, is an active volcano. Mount Terror, about eastward, is an extinct volcano. Mount Bird rises to just south of Cape Bird. Ross Island lies within the boundary of Ross Dependency, an area of Antarctica claimed by New Zealand. However, the claim is currently in abeyance by the International Antarctic Treaty System of 1961. Signatories of this treaty essentially agree that Antarctica is used for peaceful and scientific purposes. The United States and New Zealand each established bases, McMurdo and Scott, in the mid 1950s on Ross Island; the former is now the largest human settlement in Antarctica since its founding. The island is also home to early exploration shacks and memori ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Coalescence (physics)
Coalescence is the process by which two or more droplets, bubbles, or particles merge during contact to form a single daughter droplet, bubble, or particle. Coalescence manifests itself from a microscopic scale in meteorology to a macroscopic scale in astrophysics. For example, it is seen in the formation of raindrops as well as planetary and star formation. In meteorology, its role is crucial in the formation of rain. As droplets are carried by the updrafts and downdrafts in a cloud, they collide and coalesce to form larger droplets. When the droplets become too large to be sustained on the air currents, they begin to fall as rain. Adding to this process, the cloud may be seeded with ice from higher altitudes, either via the cloud tops reaching , or via the cloud being seeded by ice from cirrus clouds. Contrast-enhanced ultrasound in medicine applies microscopic bubbles for imaging and therapy. Coalescence of ultrasound contrast agent microbubbles is studied to pre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
Magma
Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma (sometimes colloquially but incorrectly referred to as ''lava'') is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural satellites. Besides molten rock, magma may also contain suspended crystals and volcanic gas, gas bubbles. Magma is produced by melting of the mantle (geology), mantle or the Crust (geology), crust in various tectonics, tectonic settings, which on Earth include subduction zones, continental rift (geology), rift zones, mid-ocean ridges and Hotspot (geology), hotspots. Mantle and crustal melts migrate upwards through the crust where they are thought to be stored in magma chambers or trans-crustal crystal mush, crystal-rich mush zones. During magma's storage in the crust, its composition may be modified by Fractional crystallization (geology), fractional crystallization, contaminati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] [Amazon] |
