- Scientists continue to research the existence of underwater volcanoes.
- In 2012, an underwater volcano called Havre erupted, located in the middle of the Pacific Ocean, but many are unaware of the incident.
- Scientists estimate, the amount of lava that the mountain spewed gunung [Havre] in the form of pumice stone and ash, about 1.5 times the eruption of Mount St. Helens in 1980.
- In Indonesia, as many as eight underwater volcanoes have been detected, the height is more than 1,000 meters and has a conical shape.
About 900 meters below sea level, in the middle of the Pacific Ocean, lies the world’s largest volcano, Havre. In 2012, this underwater volcano erupted violently. This is the largest underwater eruption ever recorded in modern times. Scientists estimate the amount of spewed lava, pumice, as well as ash, is about 1.5 times the eruption of Mount St. Helens in 1980.
However, despite its enormous size and power, not many people know about the eruption. In fact, many of us have probably never heard of Mount Havre, as quoted from Smithsonian.
When the eruption occurred, an airplane passenger on a commercial flight, coincidentally glanced out the window, and saw oddly colored patches on the surface of the ocean. At that time, the plane was approximately 800 km north of Auckland, New Zealand.
The passenger thought it might be a layer of oil, or maybe large ships floating. Upon closer inspection, it was volcanic rock spewed from below, a sign of a volcanic eruption. The passenger then took photos and sent them to geologists, which sparked an international ‘hunt’ for the origin of the eruption.
An unexpected discovery, because more than 70 percent of all such volcanic eruptions occur under the sea and scientists are clueless about understanding them. This is because, the eruption is hidden from view hundreds or even thousands of meters from the surface of the water.
Read: The Eruption of this Underwater Volcano Reveals a Natural Phenomenon
In 2015, scientists sailed to the site of the Mount Havre eruption on a mission to study the phenomenon. Through the camera lens of a remotely operated vehicle, an astonishing and terrifying sight is revealed.
Huge chunks of volcanic pumice, some the size of an MPV car, were strewn on the seabed, and thin ash spewed out from the top of the volcano. Lava appears to emerge from several large and small holes, sometimes piling up into domes. An unexpected apparition.
“It was a sight beyond our imagination,” explains Rebecca Carey, researcher at the University of Tasmania and co-author of the study exploring the Havre volcano from a remotely operated vehicle. “With the investigation of the seafloor, there is room for some very exciting discoveries, as we don’t yet have an understanding of how underwater volcanoes operate.”
Early on in the expedition, scientists expected to find layers of pumice and ash from a highly explosive eruption on the seabed [seperti Krakatau 1883 atau Gunung St Helens 1980]. As it turned out, they found a giant pumice stone measuring one meter in size which suggests that magma foams out of the hole and breaks when it comes into contact with seawater.
In every volcanic eruption, magma [batuan cair di bawah permukaan bumi] rises from the depths of the earth to the ground or seabed. Magma contains dissolved gases, which form bubbles as the pressure on the magma decreases as it rises.
Explosive eruptions occur on land when these dissolved gases are released suddenly – think of the bubbles in a coke bottle, bursting out when the bottle is shaken open, the pressure released all at once.
Read: 91 Volcanoes Found Under Antarctic Ice Sheet. This is a scientist’s concern
Under the sea, the events are different. The magma still faces the crushing pressure of tons of seawater once it reaches the bottom. The Havre volcano, which stretches between 900 and 1,200 meters below sea level, is under pressure between 92 and 122 times that of sea level. Scientists suspect that these conditions reduce the explosive power and form various types of lava formations.
Not only does pressure change how lava forms, but the interactions between water and cooling magma are also very different than when magma interacts with air. When water hits hot magma, at 800 degrees Celsius, it evaporates in an instant.
Its rapid expansion into steam can be strong enough to break apart lava. On the other hand, when magma comes into contact with water, the temperature change is so dramatic that the magma immediately freezes in the cooling process.
Many underwater volcanoes are located near areas of plate tectonic formation, known as mid-ocean ridges [mid-ocean ridge]. Volcanoes in the mid-ocean ridges alone are estimated to account for 75% of output magma on Earth.
Volcanic activity during the Holocene Period [12.000 hingga 11.500 tahun lalu] has been documented on only 119 underwater volcanoes. However, experts estimate there may be more than a million geologically young underwater volcanoes on the seabed, though most are inactive.
Read: Ancient Volcanic Eruptions Trigger Mass Extinction on Earth
In the first two decades of this century, NOAA’s Office of Ocean Exploration has funded the exploration of underwater volcanoes, with the Ring of Fire mission to the Mariana Arc in the Pacific Ocean as the primary objective.
Menggunakan Remote Operated Vehicles [ROV], scientists study underwater eruptions, pools of molten sulfur, black chimneys and even marine life adapted to this deep and hot environment.
Research from the KAIKO ROV off the coast of Hawaii shows that Mount Pahoehoe’s lava flows occur underwater, and the degree of inclination of the subsea terrain and the rate of lava supply determines the shape of the resulting lobe.
In August 2019, reportedly a floating pumice rock in the South Pacific between Fiji and Tonga. Subsequent scientific investigation revealed that the pumice came from a nearby underwater volcanic eruption, which was directly observed as a volcanic plume in satellite imagery.
The discovery will help scientists better predict precursors of underwater eruptions, such as low-frequency earthquakes or hydrophone data, using technology. machine learning.
Also read: “Angry” Fish Inhabiting Underwater Volcanoes
Underwater volcano in Indonesia
Some time ago, the Geospatial Information Agency [BIG] together with a number of ministries and agencies studied the discovery of eight of the hundreds of underwater mountains in Indonesia.
BIG Marine Mapping Coordinator Fajar Mugiarto revealed that these eight underwater mountains are located in the waters west of Sumatra, North Sulawesi and East Nusa Tenggara. [NTT], as quoted from detik.com.
Here are eight underwater mountains which have been reviewed and submitted by BIG to be included in the Gazeter of the Republic of Indonesia:
- Maselihe Underwater Mountain in North Sulawesi
- Naung Underwater Mountain in North Sulawesi
- West Kawio Seamount in North Sulawesi
- Roa Underwater Mountain in North Sulawesi
- Pagai Underwater Mountain in the waters west of Sumatra
- Baruna Komba Underwater Mountain in NTT
- The Mother Komba Underwater Mountain in NTT, and
- Abang Komba Underwater Mountain in NTT
Fajar explained that the eight mountains were categorized as volcanoes. However, according to him, in order to ascertain whether the underwater volcano is active or not, it must be studied further by the more competent ministry.
The study of these eight underwater volcanoes refers to the B-6 Standardization of Undersea Features Names document from the International Hydrographic Organization [IHO]. From the aspect of geometry, the eight mountains studied can be categorized as seamounts because they have a height of more than 1,000 meters and have a conical shape. [Berbagai sumber]
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