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1984 Eruption Of Mauna Loa
The 1984 eruption of Mauna Loa was a Hawaiian eruption in the U.S. state of Hawaii that lasted from March 25 to April 15, 1984. It ended a 9-year period of quiescence at the volcano and continued for 22 days, during which time lava flows and lava fountains issued from the summit caldera and fissures along the northeast and southwest rift zones. Although the lava threatened Hilo, the flow stopped before reaching the outskirts of town. Precursors Repeated deformation measurements showed that the summit area of Mauna Loa began to inflate shortly after a brief summit eruption on July 5–6, 1975. This was followed by a 3-year period of slowly increasing earthquake activity beneath the volcano that included a swarm of earthquakes deep in mid-September 1983. The earthquakes reached a maximum frequency just after a 6.6 magnitude earthquake took place beneath the southeast flank of Mauna Loa, in the Ka‘ōiki fault system, on November 16, 1983. Following the Ka‘ōiki earthquake, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lava Fountain
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or underwater, usually at temperatures from . The volcanic rock resulting from subsequent cooling is also often called ''lava''. A lava flow is an outpouring of lava during an effusive eruption. (An explosive eruption, by contrast, produces a mixture of volcanic ash and other fragments called tephra, not lava flows.) The viscosity of most lava is about that of ketchup, roughly 10,000 to 100,000 times that of water. Even so, lava can flow great distances before cooling causes it to solidify, because lava exposed to air quickly develops a solid crust that insulates the remaining liquid lava, helping to keep it hot and inviscid enough to continue flowing. The word ''lava'' comes from Italian and is probably derived from the Latin word ''labes'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1975 Eruption Of Mauna Loa
The 1975 eruption of Mauna Loa was a short-lived Hawaiian eruption that followed 25 years of quiescence at the Hawaiian volcano Mauna Loa. The eruption began just before midnight on July 5 and involved fissures extending across the length of Moku‘āweoweo, Mauna Loa's summit caldera, and into the upper ends of the volcano's northeast and southwest rift zones. After only 6 hours, activity in Moku‘āweoweo and on the southwest rift zone ended, but lava fountaining continued along the northeast rift zone until 7:30 p.m. on July 6, when all activity ceased. Precursors No unusual activity was noted on the Mauna Loa seismograms during the early evening of July 5; seismicity was at relatively low levels. At 23:18 HST, however, seismic alarms, signifying prolonged high-amplitude volcanic tremor, were activated in homes of Hawaiian Volcano Observatory (HVO) staff. The tremor had been first recorded by three seismometers near Moku‘āweoweo at 22:51 HST. Staff reached HVO at 23:3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lava Channel
A lava channel is a stream of fluid lava contained within zones of static (i.e., solid and stationary) lava or lava levees. The initial channel may not contain levees per se, until the parental flow solidifies over what develops into the channel and creates natural levees. This initial levee allows for the building of a more complex levee and channel. As the lava flows through the channel, the elevation of the surface of the lava flow pulsates and lava can possibly flood the associated channel walls spilling out of the channel and over the existing levees, creating what is known as overflow levees. Overflow levees increase the height and width of the original levee. The lava that flows in lava channels is commonly basaltic in composition. See also *Lava tube A lava tube, or pyroduct, is a natural conduit formed by flowing lava from a volcanic vent that moves beneath the hardened surface of a lava flow. If lava in the tube empties, it will leave a cave. Formation A lava tube ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Methane
Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Earth makes it an economically attractive fuel, although capturing and storing it poses technical challenges due to its gaseous state under normal conditions for temperature and pressure. Naturally occurring methane is found both below ground and under the seafloor and is formed by both geological and biological processes. The largest reservoir of methane is under the seafloor in the form of methane clathrates. When methane reaches the surface and the atmosphere, it is known as atmospheric methane. The Earth's atmospheric methane concentration has increased by about 150% since 1750, and it accounts for 20% of the total radiative forcing from all of the long-lived and globally mixed greenhouse gases. It has also been detected on other plane ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hilo
Hilo () is a census-designated place (CDP) and the largest settlement in Hawaii County, Hawaii, Hawaii County, Hawaii, United States, which encompasses the Hawaii (island), Island of Hawaii. The population was 44,186 according to the 2020 United States Census, 2020 census. It is the fourth-largest settlement in the state of Hawaii and largest settlement in the state outside of Oahu. Hilo is the county seat of the County of Hawaii and is in the District of South Hilo. The city overlooks Hilo Bay and has views of two shield volcanoes, Mauna Loa, an active volcano, and Mauna Kea, a dormant volcano. Mauna Kea is the site of some of the world's most important ground-based astronomical Mauna Kea Observatories, observatories. The Hilo bay-front has been destroyed by tsunamis twice. The majority of human settlement in Hilo stretches from Hilo Bay to Waiākea-Uka, on the flanks of the volcanoes. Hilo is home to the University of Hawaii at Hilo, University of Hawaii at Hilo, ʻImiloa Astr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1984 Mauna Loa Eruption (16285896735)
Events January * January 1 – The Bornean Sultanate of Brunei gains full independence from the United Kingdom, having become a British protectorate in 1888. * January 7 – Brunei becomes the sixth member of the Association of Southeast Asian Nations (ASEAN). * January 10 ** The United States and the Vatican City, Vatican (Holy See) restore full diplomatic relations. ** The Victoria, Seychelles, Victoria Agreement is signed, institutionalising the Indian Ocean Commission. *January 24 – Steve Jobs launches the Macintosh 128K, Macintosh personal computer in the United States. February * February 3 ** Dr. John Buster and the research team at Harbor–UCLA Medical Center announce history's first embryo transfer from one woman to another, resulting in a live birth. ** STS-41-B: Space Shuttle Challenger, Space Shuttle ''Challenger'' is launched on the 10th Space Shuttle mission. * February 7 – Astronauts Bruce McCandless II and Robert L. Stewart make the first untethered spac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Military Satellite
A military satellite is an artificial satellite used for a military purpose. The most common missions are intelligence gathering, navigation and military communications. The first military satellites were photographic reconnaissance missions. Some attempts were made to develop satellite based weapons but this work was halted in 1967 following the ratification of international treaties banning the deployment of weapons of mass destruction in orbit. As of 2013, there are 950 satellites of all types in Earth orbit. It is not possible to identify the exact number of these that are military satellites partly due to secrecy and partly due to dual purpose missions such as GPS satellites that serve both civilian and military purposes. As of December 2018 there are 320 known military or dual-use satellites in the sky, half of which are owned by the US, followed by Russia, China and India (13). [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mauna Loa Erupting At Night, 1984 , cinder cone of Haleakalā
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Mauna or Mouna may refer to: * ''Mauna'' (moth), genus of moths in the family Geometridae * Mauna (silence), silence in Hindu philosophy * Mauna, Käbschütztal, village in Käbschütztal, Germany * A Hawaiian word for mountain, used in the following Hawaiian volcano names: ** Mauna Loa, on Hawai'i ** Mauna Kea, on Hawai'i ** Mauna Ulu, cinder cone of Kīlauea, on Hawai'i ** Mauna Iki, cinder cone of Kīlauea, on Hawai'i ** Mauna Haleakalā, on Maui ** Mauna Hina Mauna or Mouna may refer to: * ''Mauna'' (moth), genus of moths in the family Geometridae * Mauna (silence), silence in Hindu philosophy * Mauna, Käbschütztal, village in Käbschütztal, Germany * A Hawaiian word for mountain, used in the follo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mauna Kea
Mauna Kea ( or ; ; abbreviation for ''Mauna a Wākea''); is a dormant volcano on the island of Hawaii. Its peak is above sea level, making it the highest point in the state of Hawaii and second-highest peak of an island on Earth. The peak is about higher than Mauna Loa, its more massive neighbor. Mauna Kea is unusually topographically prominent for its height: its wet prominence is fifteenth in the world among mountains, at ; its dry prominence of is second in the world, only after Mount Everest This dry prominence is greater than Mount Everest's height above sea level of , and some authorities have labelled Mauna Kea the tallest mountain in the world, from its underwater base. It is about one million years old and thus passed the most active shield stage of life hundreds of thousands of years ago. In its current post-shield state, its lava is more viscous, resulting in a steeper profile. Late volcanism has also given it a much rougher appearance than its neighboring v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mauna Kea Observatories
The Mauna Kea Observatories (MKO) are a group of independent astronomical research facilities and large telescope observatories that are located at the summit of Mauna Kea on the Big Island of Hawaiʻi, United States. The facilities are located in a 525-acre (212 ha) special land use zone known as the "Astronomy Precinct", which is located within the 11,228-acre (4,544 ha) Mauna Kea Science Reserve. The Astronomy Precinct was established in 1967 and is located on land protected by the Historical Preservation Act for its significance to Hawaiian culture. The presence and continued construction of telescopes is highly controversial due to Mauna Kea's centrality in native Hawaiian religion and culture, as well as for a variety of environmental reasons. The location is near ideal because of its dark skies from lack of light pollution, good astronomical seeing, low humidity, high elevation of , position above most of the water vapor in the atmosphere, clean air, good weath ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seismic Station
A seismometer is an instrument that responds to ground noises and shaking such as caused by earthquakes, volcanic eruptions, and explosions. They are usually combined with a timing device and a recording device to form a seismograph. The output of such a device—formerly recorded on paper (see picture) or film, now recorded and processed digitally—is a seismogram. Such data is used to locate and characterize earthquakes, and to study the Earth's internal structure. Basic principles A simple seismometer, sensitive to up-down motions of the Earth, is like a weight hanging from a spring, both suspended from a frame that moves along with any motion detected. The relative motion between the weight (called the mass) and the frame provides a measurement of the vertical ground motion. A rotating drum is attached to the frame and a pen is attached to the weight, thus recording any ground motion in a seismogram. Any movement from the ground moves the frame. The mass tends not to m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Volcanic Tremor
A harmonic tremor is a sustained release of seismic and infrasonic energy typically associated with the underground movement of magma, the venting of volcanic gases from magma, or both. It is a long-duration release of seismic energy, with distinct spectral lines, that often precedes or accompanies a volcanic eruption. More generally, a volcanic tremor is a sustained signal that may or may not possess these harmonic spectral features. Being a long-duration continuous signal from a temporally extended source, a volcanic tremor contrasts distinctly with transient sources of seismic radiation, such as tremors that are typically associated with earthquakes and explosions. The relation between long-period events and an imminent eruption was first observed by Bernard Chouet, a volcanologist who was working at the United States Geological Survey.U.S. TV program on use of long-period events to predict volcanic eruptions: "Nova: Volcano's Deadly Warning": https://www.pbs.org/wgbh/nova ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
