A major eruption of Mt Taranaki could lead to devastating pyroclastic flows in a wider area than originally thought up, which has threatened a large number of people.
The pyroclastic flow is a gas, ash and rock, heated by a hurricane. erupting volcano and burn everything in its path.
On the Mount of Taranaki and other volcanoes, as it is all over the world, scientists have long predicted that these streams can spread only 1
The University of Auckland researchers has advanced this limit to 25 km, with serious consequences for populated areas in hazardous areas.
New estimates have put many cities in Taranaki at risk, although the main areas of New Plymouth were protected by the building of the Puakai Highest Volcano
Mt Taranaki was considered the most likely New Zealand volcano to cause national consequences throughout our lives, with a 50% probability of eruption during subsequent 50 years old. According to the current estimates, more than 85,000 people live within 30 km of the mountain and 40,000 in areas with high priority for evacuation.
Fresh data was presented to the joint scientific advisory group on volcanic eruptions of Taranaki, and now work is under way with
The leader of the new study, graduate student Jeff Lerner, was able to shed light on this explosive history. , applying methods of paleomagnetism – or recording magnetic signals stored in volcanic rocks.
"Due to the difficulty of understanding what caused deposition away from volcanoes, scientists in the past in Taranaki have never been able to finally determine the deposition of the hot pyroclastic flow," Lerner said.
"We have tried a paleomagnetic method, which nobody tried before in Mt Taranaki before, focusing on some fields with other characteristics that correspond to hot fluxes."
After exploding from the volcano, they recorded a signal from the Earth's magnetic field at that time, leaving scientists with some important clues about the direction in which the rocks passed.
"If they rotate after cooling, for example, in a volcanic flow or
" If they travel while they are still very hot and settle together, for example, within the pyroclastic flow, they are then cooled down and all the particles have magnetic alignment.
] "We can later check whether the particles are lined up or not, which can tell us whether the deposit was a pyroclastic flow or not."
Using complex laboratory equipment for heating and measuring rock samples many times, Lerner and colleagues were able to restore the temperature at which the rock was laid.
"We discovered that magnetic directions in several different sections from 15 km to 20 km from the volcano were lined, which means they were from pyroclastic streams."
The team also collected new samples of coal from deposits for radiocarbon dating, which put them around 11,500 years ago – and was associated with one of the largest eruptions of Taranaki over 30,000 years.
"We believe that such long pyroclastic flows are possible only in the largest 15% of the Taranaki eruptions, which occur on average every 1000 years."
Head Lerner, a professor of volcanology at the University of Auckland, Professor Shane Kronin, said that a major major eruption would disrupt the Ir and ground transport, tourism, agriculture, energy supply and water supply across the North Island.
Although the event could have been expected in the relatively near future, the calm after the last major blow of Taranaki was one of his about 1790
Recently, the same research group found that Mount Taranaki was in the second longest gap between eruptions for more than 1200 years of records.
"Thus, we do not have the modern experience of his typically very long eruptions."
"Studies have shown that as soon as Taranaki begins to erupt, it lasts for many years, decades or centuries."
The volcano began to erupt about 130,000 years ago, with large eruptions occurring on average every 500 years and less eruptions of about 90 years apart.
The recent assessment of net losses in economic activity from the short-lived eruption of Taranaki was roughly estimated to range from $ 1.7 to $ 4 billion – or $ 13 billion to $ 26 billion over ten years
Kronin, director of national scientific cooperation, aimed at making New Zealand more susceptible to natural hazards, said that the broader research program in Taranaki offers scientific knowledge that is also important for engineering and socio-economic issues.
"By utilizing the new integration of volcanic scientific knowledge, experiments and advanced mathematical and economic modeling, we seek to radically reduce the uncertainty that impedes the resolution of danger and the planning of the death penalty." The Bulletin of the Geological Society of America had potential consequences for other volcanoes in New Zealand and abroad.
About 29 million people around the world live within a radius of 10 km from an active volcano, and 229 million live within a radius of 30 km.