Mauna Kea typically is a volcano on the island of Hawaii. Standing four,205 m (13,796 ft) above sea level, its peak is the actual highest point within the state of Hawaii. Though, a great deal of the mountain is actually below water; whenever calculated from its oceanic base, Mauna Kea typically is over 10,200 m (33,500 ft) tall-significantly taller than Mount Everest typically is above sea level. Mauna Kea is regarding a million years of age, as well as has thus passed the actual many active shield stage of lifetime hundreds of thousands of many years ago. Within its present post-shield state, its lava is a bit more viscous, resulting in a steeper profile. Late volcanism has as well provided it a lot rougher appearance compared to its neighboring volcanoes; contributing factors include the particular construction of cinder cones, the particular decentralization of its rift zones, the actual glaciation about its peak, plus the weathering effects of the prevailing trade winds. Mauna Kea endure erupted four,000 to be able to 6,000 many years ago. Based on the USGS, because of January 2012, the Volcanic-Alert Level typically is “Normal”.
In Hawaiian mythology, the peaks of the island of Hawaii usually are sacred, plus Mauna Kea is actually the actual most sacred of every. An historic legislation permitted just high-ranking tribal chiefs to be able to go to its peak. Historic Hawaiians living found on the slopes of Mauna Kea relied on its extensive forests for food, plus quarried the dense volcano-glacial basalts about its flanks for tool creation. When Europeans arrived within the late 18th century, settlers introduced cattle, sheep and game animals, several of which was feral and even began to be able to damage the actual mountain’s ecology. Mauna Kea is ecologically separated into three sections: a great alpine climate at its summit, a Sophora chrysophylla-Myoporum sandwicense (or simply mamane-naio) forest about its flanks, and also a particular Acacia koa-Metrosideros polymorpha (or simply koa-?ohi?a) woodland, now mostly cleared by the actual previous sugar industry, at its base. In recent many years, concern over the particular vulnerability of the native species has led to court situations which currently have forced the particular Hawaii Department of Land and in addition All-natural Resources to be able to eradicate just about all feral species about the mountain.
Alongside its significant altitude, dry environment, plus stable airflow, Mauna Kea’s summit is regarded as the actual best sites within the world for astronomical observation, and also one of several most controversial. Because the creation of a great access road within 1964, thirteen telescopes funded by eleven nations have been designed at the particular summit. The actual Mauna Kea Observatories usually are used for scientific research across the actual electromagnetic spectrum from visible light with radio, and comprise the particular largest these center within the world. Their construction about a “sacred landscape”, replete with endangered species and additionally ongoing cultural practices, continues to be a topic of debate and additionally protest. Research are generally underway in order to determine their effect found on the summit ecology.
Mauna Kea typically is one of five hotspot volcanoes which shape the island of Hawaii, the actual largest and also youngest island associated with the Hawaiian-Emperor seamount chain. Of many of these five volcanoes, Mauna Kea typically is the actual fourth oldest and additionally fourth many active. It began because a preshield volcano driven by the Hawaii hotspot about one million many years ago, and also became extremely active during its protect stage until 500,000 many years ago. Mauna Kea registered its quieter post-shield stage 250,000 with 200,000 many years ago, as well as is currently dormant.
Mauna Kea typically is over three,200 km3 (770 cu mi) with regard to volume, and so massive it and its neighbor, Mauna Loa, depress the actual ocean crust below it by 6 km (4 mi). The volcano continues to slip and also flatten beneath its own body weight at a rate of less than 0.2 mm (0.01 in) per year. A great deal of its mass lies east of its present summit. Mauna Kea stands four,205 m (13,800 ft) above sea degree, really 35 m (110 ft) high compared to its neighbor Mauna Loa. Calculated from its base found on the ocean floor, it rises over 10,000 m (33,000 ft), significantly greater compared to the particular elevation of Mount Everest above sea level, and additionally is the particular highest point in the state of Hawaii.
Like just about all Hawaiian volcanoes, Mauna Kea has been created by the particular Hawaiian hotspot, as the actual Pacific tectonic plate has relocated over a hotspot within the Earth’s fundamental mantle. The actual Hawaii island volcanoes are really only the latest evidence of this procedure which, over 70 million many years, has built the particular 6,000 km (3,700 mi)-long Hawaiian Ridge – Emperor Seamount chain. The prevailing, though certainly not completely settled, view typically is that the particular hotspot happens to be mostly stationary inside the planet’s mantle for much, in the event that certainly not almost all of the Cenozoic Era. Though, whilst Hawaiian volcanism is well-understood and extensively studied, right now there remains no definite explanation of the system that causes the actual hotspot impact.
Lava flows from Mauna Kea overlapped throughout complex levels alongside all those of its friends during the course of its growth. The majority of prominently, Mauna Kea is built upon elderly flows from Kohala to the actual northwest, and in addition intersects the base of Mauna Loa in order to the south. The actual original eruptive fissures (rift zones) within the flanks of Mauna Kea were buried by its post-shield volcanism. Hilo Ridge, a prominent underwater rift zone structure east of Mauna Kea, had been once believed to be a part of the volcano; nevertheless, it is actually at this point understood in order to be a rift zone of Kohala that happens to be impaired by more youthful Mauna Kea flows.
The shield-stage lavas which built the actual massive key mass associated with the mountain happen to be tholeiitic basalts, like all those of Mauna Loa, created through the particular mixing of main magma and also subducted oceanic crust. They happen to be covered by the particular oldest exposed rock strata on Mauna Kea, the post-shield alkali basalts associated with the Hamakua Volcanics, which erupted between 250,000 not to mention 70-65,000 many years ago. The latest volcanic flows tend to be hawaiites and even mugearites: they tend to be the particular post-shield Laupahoehoe Volcanics, erupted between 65,000 as well as four,000 years ago. Many of these changes inside lava composition accompanied the particular slow reduction of the provide of magma with the summit, which led with weaker eruptions that afterward gave option to isolated episodes associated with volcanic dormancy. The Laupahoehoe lavas are far more viscous and even contain more volatiles compared to the actual earlier tholeiitic basalts; their thicker flows significantly steepened Mauna Kea’s flanks. In addition, explosive eruptions have built cinder cones close to the summit. Many of these cones tend to be the the majority of recent eruptive centers of Mauna Kea. Its present summit is dominated by lava domes and even cinder cones up to 1.5 km (0.9 mi) within diameter and even hundreds of meters tall.
Scoria and cinder cones on Mauna Kea’s summit inside wintertime
Glacial evidence on Mauna Kea, outlining terminal moraines (“m”) and even till (“w”)
Mauna Kea is actually the actual only Hawaiian volcano alongside distinct evidence of glaciation. Synonymous deposits most likely existed on Mauna Loa, however, have been covered by later lava flows. Despite Hawaii’s tropical place, during the course of many past ice ages a drop of only a degree inside temperature enabled snow with stay at the particular mountain’s summit via summertime, triggering the particular formation of an ice cap. There are three shows of glaciation that have been recorded within the last 180,000 years: the actual Pohakuloa (180-130 ka), Waihu (80-60 ka) plus Makanaka (40-13 ka) show. Many of these have extensively sculpted the summit, depositing moraines along with a circular ring of until and in addition gravel along the mountain’s upper flanks. Subglacial eruptions built cinder cones throughout the actual Makanaka glaciation, almost all of which happened to be heavily gouged by glacial action. The particular most recent cones had been built between 9000 as well as 4500 years ago, atop the glacial deposits, although 1 study indicates which the endure eruption will currently have been around 3600 years ago.
At their maximum extent, the actual glaciers extended from the summit right down to between 3,220 not to mention 3,800 m (10,500 and also 12,500 ft) of elevation. A little body of permafrost, less than 25 m (80 ft) over, had been found at the actual summit of Mauna Kea before 1974, and also could still be present. Tiny gullies etch the summit, formed by rain- and even snow-fed streams that flow only in the course of winter melt and additionally rain showers. Found on the windward side associated with the mountain, flow erosion driven by trade winds has accelerated erosion inside a way synonymous to this on more aged Kohala.
Mauna Kea is actually dwelling to Lake Waiau, the highest lake within the Pacific Basin. At a great altitude of 3,969 m (13,022 ft), it lies in the Pu?u Waiau cinder cone and in addition is truly the only alpine lake inside Hawaii. The actual lake typically is pretty little plus shallow, with a surface community of 0.73 ha (1.80 acres) as well as a depth of 3 m (10 ft). Radiocarbon dating of samples at the base of the lake indicates it ended up being well-defined of ice 12,600 many years ago. Hawaiian lavas are generally typically permeable, preventing the formation of ponds due with infiltration. Here, either sulfur-bearing steam changed the particular volcanic ash with low-permeability clays, or alternatively explosive interactions between increasing magma and groundwater or alternatively surface drinking water (phreatic eruptions) formed exceptionally fine ash which also would lower the permeability associated with the lake bed.