The volcano is thought to have erupted less than 3 million years ago due to the subduction of the Pacific Plate deeper into the mantle of the Marina Trench. Previously, this area is thought to have contained only seamounts and islands formed million years ago. The research team initially suspected the presence of a small volcano after observing bathymetric data collected by the Japan Coast Guard. They then analyzed rock samples collected by the Shnkai, a manned submersible that can dive to depths of 6, meters, which observed the presence of volcano.
He adds, "This will tell us more about the true nature of the asthenosphere. Materials provided by Tohoku University. Note: Content may be edited for style and length. It has erupted times in the last 3, years. This is a bit misleading, however, because it was already an old volcano when the first recorded eruption occurred in 1, BC. The Island of Hawaii has two active volcanoes, Kilauea and Mauna Loa, which have been active for at least , years. Hawaii is the youngest of a long line of volcanoes called the Hawaiian-Emperor Sea Mount chain.
The oldest volcano in the chain is the inactive volcano Meiji, which is 85 million years old. Some 1, volcanoes are still considered potentially active around the world today; of those—over 10 percent—sit within the boundaries of the United States. But each volcano is different. Some burst to life in explosive eruptions, like the eruption of Mount Pinatubo , and others burp rivers of lava in what's known as an effusive eruption, like the activity of Hawaii's Kilauea volcano.
These differences are all thanks to the chemistry driving the molten activity. Effusive eruptions are more common when the magma is less viscous, or runny, which allows gas to escape and the magma to flow down the volcano's slopes. Explosive eruptions, however, happen when viscous molten rock traps the gasses, building pressure until it violently breaks free. The majority of volcanoes in the world form along the boundaries of Earth's tectonic plates—massive expanses of our planet's lithosphere that continually shift, bumping into one another.
When tectonic plates collide, one often plunges deep below the other in what's known as a subduction zone. As the descending landmass sinks deep into the Earth, temperatures and pressures climb, releasing water from the rocks.
The water slightly reduces the melting point of the overlying rock, forming magma that can work its way to the surface—the spark of life to reawaken a slumbering volcano. Not all volcanoes are related to subduction, however. Another way volcanoes can form is what's known as hotspot volcanism.
In this situation, a zone of magmatic activity —or a hotspot—in the middle of a tectonic plate can push up through the crust to form a volcano. Although the hotspot itself is thought to be largely stationary, the tectonic plates continue their slow march, building a line of volcanoes or islands on the surface.
This mechanism is thought to be behind the Hawaii volcanic chain. Some 75 percent of the world's active volcanoes are positioned around the ring of fire , a 25,mile long, horseshoe-shaped zone that stretches from the southern tip of South America across the West Coast of North America, through the Bering Sea to Japan, and on to New Zealand.
This region is where the edges of the Pacific and Nazca plates butt up against an array of other tectonic plates. Importantly, however, the volcanoes of the ring aren't geologically connected. In other words, a volcanic eruption in Indonesia is not related to one in Alaska, and it could not stir the infamous Yellowstone supervolcano. Volcanic eruptions pose many dangers aside from lava flows. It's important to heed local authorities' advice during active eruptions and evacuate regions when necessary.
In the months that followed, European weather went haywire. In Germany, it rained so heavily that corpses surfaced in cemeteries. In the town of Thorn, Poland, the inhabitants took to travelling the streets by boat. In the unrelenting rain, the castle cellars of Teutonic knights were flooded and whole villages were swept away.
Four years later, Europe was hit by a mini ice age. Fish froze in their ponds. In Bologna, Italy, heavy snow forced locals to travel with their horses and carriages along the frozen waterways. Many thousands of miles away in the tropics, a giant volcano was making geological history. This was an eruption so big, it produced an ash cloud which enveloped the Earth and led to the coolest decade for centuries.
The blast itself would have been heard up to 2,km 1, miles away and created a tsunami which caused devastation hundreds of kilometres away. In terms of scale, it surpassed even the eruption of Tambora, which unleashed energy equivalent to 2. Traces of the eruption have been found from Antarctica to Greenland. There it was locked into the ice, forming part of a natural record of geological activity that spans millennia. But establishing its existence is the easy part.
This is a true geological mystery, one which has left geologists scratching their heads for decades. It all began with a rumour and a coral-fringed island in the South Pacific. Back in the s, archaeologists visiting Tongoa, Vanuatu heard stories of an ancient landmass which, many generations ago, linked it to the neighbouring island of Epi.
It was known as Kuwae — and in the centre was a giant volcano.
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