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Mauna Loa
Mauna Loa ( or ; Hawaiian: ; en, Long Mountain) is one of five volcanoes that form the Island of Hawaii in the U.S. state of Hawaii in the Pacific Ocean. The largest subaerial volcano (as opposed to subaqueous volcanoes) in both mass and volume, Mauna Loa has historically been considered the largest volcano on Earth, dwarfed only by Tamu Massif. It is an active shield volcano with relatively gentle slopes, with a volume estimated at , although its peak is about lower than that of its neighbor, Mauna Kea. Lava eruptions from Mauna Loa are silica-poor and very fluid, and tend to be non-explosive. Mauna Loa has probably been erupting for at least 700,000 years, and may have emerged above sea level about 400,000 years ago. The oldest-known dated rocks are not older than 200,000 years. The volcano's magma comes from the Hawaii hotspot, which has been responsible for the creation of the Hawaiian island chain over tens of millions of years. The slow drift of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hualālai
Hualālai (pronounced in Hawaiian) is an active volcano on the island of Hawaii in the Hawaiian Islands. It is the westernmost, third-youngest and the third-most active of the five volcanoes that form the island of Hawaii, following Kīlauea and the much larger Mauna Loa. Its peak stands above sea level. Hualālai is estimated to have risen above sea level about 300,000 years ago. Despite maintaining a very low level of activity since its last eruption in 1801, and being unusually inactive for the last 2,000 years, Hualālai is still considered active, and is expected to erupt again some time within the next century. The relative unpreparedness of the residents in the area caused by the lull in activity would worsen the consequences of such an event. The area near the volcano has been inhabited for centuries by Hawaiian natives, dating back to before recorded history. The coast west of Hualālai in particular had several royal complexes. The volcano is also important eco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tamu Massif
Tamu Massif is a seamount in the northwest Pacific Ocean, sitting atop a triple junction of mid-ocean ridges. Tamu Massif is located in the about east of . The massif covers an area of about . Its summit is about below the surface of the ocean, and its base extends to about deep. It is about tall. , a marine geophysicist from the Department of Earth and Atmospheric Sciences at the |
The Washington Post
''The Washington Post'' (also known as the ''Post'' and, informally, ''WaPo'') is an American daily newspaper published in Washington, D.C. It is the most widely circulated newspaper within the Washington metropolitan area and has a large national audience. Daily broadsheet editions are printed for D.C., Maryland, and Virginia. The ''Post'' was founded in 1877. In its early years, it went through several owners and struggled both financially and editorially. Financier Eugene Meyer purchased it out of bankruptcy in 1933 and revived its health and reputation, work continued by his successors Katharine and Phil Graham (Meyer's daughter and son-in-law), who bought out several rival publications. The ''Post'' 1971 printing of the Pentagon Papers helped spur opposition to the Vietnam War. Subsequently, in the best-known episode in the newspaper's history, reporters Bob Woodward and Carl Bernstein led the American press's investigation into what became known as the Watergate scandal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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] |
Pacific Plate
The Pacific Plate is an oceanic tectonic plate that lies beneath the Pacific Ocean. At , it is the largest tectonic plate. The plate first came into existence 190 million years ago, at the triple junction between the Farallon, Phoenix, and Izanagi Plates. The Pacific Plate subsequently grew to where it underlies most of the Pacific Ocean basin. This reduced the Farallon Plate to a few remnants along the west coast of North America and the Phoenix Plate to a small remnant near the Drake Passage, and destroyed the Izanagi Plate by subduction under Asia. The Pacific Plate contains an interior hot spot forming the Hawaiian Islands. Boundaries The north-eastern side is a divergent boundary with the Explorer Plate, the Juan de Fuca Plate and the Gorda Plate forming respectively the Explorer Ridge, the Juan de Fuca Ridge and the Gorda Ridge. In the middle of the eastern side is a transform boundary with the North American Plate along the San Andreas Fault, and a boundary with the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plate Tectonics
Plate tectonics (from the la, label=Late Latin, tectonicus, from the grc, τεκτονικός, lit=pertaining to building) is the generally accepted scientific theory that considers the Earth's lithosphere to comprise a number of large tectonic plates which have been slowly moving since about 3.4 billion years ago. The model builds on the concept of ''continental drift'', an idea developed during the first decades of the 20th century. Plate tectonics came to be generally accepted by geoscientists after seafloor spreading was validated in the mid to late 1960s. Earth's lithosphere, which is the rigid outermost shell of the planet (the crust and upper mantle), is broken into seven or eight major plates (depending on how they are defined) and many minor plates or "platelets". Where the plates meet, their relative motion determines the type of plate boundary: '' convergent'', '' divergent'', or ''transform''. Earthquakes, volcanic activity, mountain-building, and oceanic tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hawaiian Islands
The Hawaiian Islands ( haw, Nā Mokupuni o Hawai‘i) are an archipelago of eight major islands, several atolls, and numerous smaller islets in the North Pacific Ocean, extending some from the island of Hawaii in the south to northernmost Kure Atoll. Formerly the group was known to Europeans and Americans as the Sandwich Islands, a name that James Cook chose in honor of the 4th Earl of Sandwich, the then First Lord of the Admiralty. Cook came across the islands by chance when crossing the Pacific Ocean on his Third Voyage in 1778, on board HMS ''Resolution''; he was later killed on the islands on a return visit. The contemporary name of the islands, dating from the 1840s, is derived from the name of the largest island, Hawaii Island. Hawaii sits on the Pacific Plate and is the only U.S. state that is not geographically connected to North America. It is part of the Polynesia subregion of Oceania. The state of Hawaii occupies the archipelago almost in its entirety (includin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hawaii Hotspot
The Hawaii hotspot is a volcanic hotspot located near the namesake Hawaiian Islands, in the northern Pacific Ocean. One of the best known and intensively studied hotspots in the world, the Hawaii plume is responsible for the creation of the Hawaiian–Emperor seamount chain, a mostly undersea volcanic mountain range. Four of these volcanoes are active, two are dormant; more than 123 are extinct, most now preserved as atolls or seamounts. The chain extends from south of the island of Hawaii to the edge of the Aleutian Trench, near the eastern coast of Russia. While most volcanoes are created by geological activity at tectonic plate boundaries, the Hawaii hotspot is located far from plate boundaries. The classic hotspot theory, first proposed in 1963 by John Tuzo Wilson, proposes that a single, fixed mantle plume builds volcanoes that then, cut off from their source by the movement of the Pacific Plate, become increasingly inactive and eventually erode below sea level over mi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magma
Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma 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 gas bubbles. Magma is produced by melting of the mantle or the crust in various tectonic settings, which on Earth include subduction zones, continental rift zones, mid-ocean ridges and hotspots. Mantle and crustal melts migrate upwards through the crust where they are thought to be stored in magma chambers or trans-crustal crystal-rich mush zones. During magma's storage in the crust, its composition may be modified by fractional crystallization, contamination with crustal melts, magma mixing, and degassing. Following its ascent through the crust, magma may feed a volcano and be extruded as lava, or it may solidify underground to form an intrusion, such as a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hawaiian Eruption
A Hawaiian eruption is a type of volcanic eruption where lava flows from the vent in a relatively gentle, low level eruption; it is so named because it is characteristic of Hawaiian volcanoes. Typically they are effusive eruptions, with basaltic magmas of low viscosity, low content of gases, and high temperature at the vent. Very small amounts of volcanic ash are produced. This type of eruption occurs most often at hotspot volcanoes such as Kīlauea on Hawaii's big island and in Iceland, though it can occur near subduction zones (e.g. Medicine Lake Volcano in California, United States) and rift zones. Another example of Hawaiian eruptions occurred on the island of Surtsey in Iceland from 1964 to 1967, when molten lava flowed from the crater to the sea. Hawaiian eruptions may occur along fissure vents, such as during the eruption of Mauna Loa in 1950, or at a central vent, such as during the 1959 eruption in Kīlauea Iki Crater, which created a lava fountain 580 meters (1,900&n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silica
Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and most abundant families of materials, existing as a compound of several minerals and as a synthetic product. Notable examples include fused quartz, fumed silica, silica gel, opal and aerogels. It is used in structural materials, microelectronics (as an Insulator (electricity), electrical insulator), and as components in the food and pharmaceutical industries. Structure In the majority of silicates, the silicon atom shows tetrahedral coordination geometry, tetrahedral coordination, with four oxygen atoms surrounding a central Si atomsee 3-D Unit Cell. Thus, SiO2 forms 3-dimensional network solids in which each silicon atom is covalently bonded in a tetrahedral manner to 4 oxygen atoms. In contrast, CO2 is a linear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
United States National Geodetic Survey
The National Geodetic Survey (NGS) is a United States federal agency that defines and manages a national coordinate system, providing the foundation for transportation and communication; mapping and charting; and a large number of applications of science and engineering. Since its foundation in its present form in 1970, it has been part of the National Oceanic and Atmospheric Administration (NOAA), of the United States Department of Commerce. History The National Geodetic Surveys history and heritage are intertwined with those of other NOAA offices. It traces its history to the Survey of the Coast, which was formed in 1807 as the first scientific agency of the United States Government. It became the United States Coast Survey in 1836 and the United States Coast and Geodetic Survey in 1878, the latter name change reflecting the increasing role of geodesy in its work. Upon the creation of NOAA in 1970, the Coast and Geodetic Survey was abolished and its responsibilities were spl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
