Yellowstone deep Dive: lava flows up to 20 miles

&http://www.aliyun.com/zixun/aggregation/37954.html ">nbsp; The beauty of Yellowstone National Park is well known, but what many do not know is that it was a giant volcano in the past. Now, geologists are finally confirming that those areas of the national park are most likely to erupt again one day in the future. A new study suggests that Yellowstone's next eruption is most likely to focus on one of the 3 fault belts along the north-north west across the park. There are two areas where a super volcanic eruption took place around 174,000 years ~7, while another region has seen frequent minor earthquakes in recent years. Guillaume Girard, the first author of the study, Grim Gillard, a visiting scholar at Michigan State University, said the information was a reminder to geologists that they should focus on which areas of the park to monitor.

The Yellowstone area is often called a "super volcano" by geologists because it has in the past been a terrible record of 240 cubic miles (1000 cubic kilometres) of volcanic ash and lava that have been ejected during an explosion. Geological records show that its most recent mass outbreak occurred about 640,000 years ago. Ms Gillard noted that smaller outbreaks appeared to be more frequent, but were still less than one out of 10,000 if the rate was specific to a particular year. He judged that such eruptions would be lava-flow rather than burst eruptions. "The viscosity of these lava flows is very high, so they flow very slowly," he said. ”

Similar slow lava flows have occurred in the years after the Saint Helens, Mt. eruption, but the Yellowstone volcano will be much larger. "Some of these lava flows are about 20 miles (32 kilometers) away, and we have never seen such a massive, cyclical giant eruption in human history," Ms Gillard said. ”

The source of lava from Yellowstone

According to a study of titanium in the volcanic lava flow in Yellowstone, Ms Gillard's team determined that the source of these lava flows was rising rapidly from the depths of 6~12 kilometers underground. The titanium content in the quartz crystals inside the lava flow identifies the depth at which the crystals slowly crystallize from the underground magma chambers. So if these magma were to stagnate during the ascent, the titanium content of the magma from around to the core should be different, like a layer of onion. But Ms Gillard says there is no such feature in these crystals. This means that the magma is rapidly rising from the depths of the earth to the surface, and there is no long enough stopover in the middle of the day.

Of course, the word "fast" here is "fast" in the geological sense. From the point of view of human history, the rate of these magma rises may be considered very slow, because it will take hundreds of or even thousands of years.

So does this relatively rapid movement of magma mean that Yellowstone volcano is about to erupt? Ms Gillard said: "This is not an imminent threat." Any study has shown that there is no magma that is about to erupt in the foreseeable future. ”

Ben Ellis (Ben Ellis), a volcanic scientist from the Institute of Geochemistry and Petrology at the Federal University of Zurich, Switzerland, said Gillard's work was "very neat", but noted that the pattern of eruptions here could change significantly. He cites a series of eruptions of linear faults that have occurred in the past as cases that were similar to Ms Gillard's study, but they "may suddenly turn to areas far away from the fault line." ”