10/10/2023 0 Comments Hawaii lava flow mapMauna Loa last erupted in 1984, and in the years afterward, it stayed mostly silent, even as the smaller neighboring volcano, Kilauea, which shares the same magma plume, erupted continuously. “For the most part, when these things are not erupting, they’re quiet.” “We’re lucky if the pressure is high enough, or the system is moving fast enough that we can get clues to what’s going on there,” Dr. From this, together with data about the gases and crystals emitted during the eruption and tiny inflections in gravitational force, a picture begins to emerge from the chaos. Such deformations can be picked up by seismometers, which detect the depth and intensity of minerals vibrating and splitting under the molten pressure. Magma pushes upward more quickly, cracking rock below ground and causing the surface of the volcano to swell. Things change, though, when the volcano starts breathing. “It is not clear whether there are additional storage reservoirs at greater depths,” Dr. Satellites, while ever-improving, are not sensitive enough under normal conditions to see deeper into Mauna Loa than the shallow magma reservoir a couple of miles below the summit. “Few things on Earth are so predictable,” he added. Orcutt said, it will reliably produce volcanic activity. This hot spot has probably been fomenting volcanic activity for tens of millions of years, although it arrived in its current position under Mauna Loa only about 600,000 years ago. The instruments were able to accurately read the direction and speed of the magma’s flow the results pointed resoundingly toward the presence of a hot spot. John Orcutt, a geophysicist at the University of California, San Diego, who helped lead that research, said that the seismometers had provided an X-ray of the magma plume rising beneath Hawaii. Some confirming observations came relatively recently, in the 2000s, after scientists began placing seismometers, which measure terrestrial energy waves, on the ocean floor. “There is no other theory that is able to reconcile so many observations,” said Helge Gonnermann, a volcanologist at Rice University. The hot spot theory gained broad consensus in the subsequent decades. The results are archipelagoes like the Hawaiian-Emperor seamount chain and parts of the Iceland Plateau. ![]() The plate shifts over millions of years while the magma plume stays relatively still, creating new volcanoes atop the plate and leaving inactive ones in their wake. This “hot spot” continually pushes toward the surface, sometimes bursting through the tectonic plate, melting and deforming the surrounding rock as it goes. In 1963, a geophysicist named John Tuzo Wilson proposed that the islands, which are covered with layers of volcanic stone, sit above a magma plume, which forms when rock from the deep mantle bubbles up and pools below the crust. Hawaiian Volcano Observatory, have had to strike a careful balance between concern for public safety, given the many unknowns, and the desire to collect data. With the eruption underway, researchers on the Big Island, including Jim Kauahikaua, a volcanologist with the U.S.G.S. who monitored the mountain from 2011 to 2016, said that sheer size, mineral composition and heat all presented logistical difficulties for scientists and public officials hoping to predict its movements. ![]() Weston Thelen, a volcanologist with the U.S.G.S. Even still, so much about the inner workings of the mountain is unknown, Dr. “Mauna Loa is one of the most well-instrumented volcanoes in the United States,” said Wendy Stovall, a volcanologist with the U.S. The eruption was years in the making, matched not quite in scale by the ongoing effort to monitor the volcano with seismometers, spectrometers, tiltmeters, GPS units and other state-of-the-art tools. The curious made plans to observe what could shape up to be an event of a lifetime: the exhalation of a massive mountain. ![]() Scientists rushed to predict which areas of the island might be in danger. Public officials scrambled to alert nearby residents. Notice that Mauna Loa, the largest active volcano in the world, was going to erupt - as it did this week for the first time in nearly four decades - came to people on the Big Island of Hawaii an hour before the lava began to flow.
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