Latest news with #AlexIezzi
Yahoo
11-07-2025
- Science
- Yahoo
‘Larger swarm than anything we've seen': Rainier quakes reach historic levels
The recent swarm of small earthquakes at Mount Rainier has not only made national headlines but also history: Researchers have never recorded seismic activity like this before at the active stratovolcano. 'It's now a larger swarm than anything we've seen since we've been (seismic) monitoring anything at Mount Rainier,' Alex Iezzi, a research geophysicist, said in an interview Thursday. Researchers started seismic monitoring at Mount Rainier in the 1970s, according to Iezzi, who works for the U.S. Geological Survey's Cascades Volcano Observatory and said she conferred with other seismologists to identify the origin of observations at the mountain. Prior to then, it's unknown whether the volcano had experienced a larger swarm — a term defined as a cluster of earthquakes occurring in rapid succession in the same area. This swarm was first reported by the USGS on Tuesday morning. Since then, there have been hundreds of so-called volcano-tectonic earthquakes detected relatively deep below Mount Rainier's summit. Researchers say there's been no cause for concern or any indications that the volcano is on the verge of eruption — something that hasn't occurred in about 1,000 years. 'Which I think is good,' Iezzi added. Since Tuesday's roaring start, the seismic activity has significantly declined and continued to dwindle into Friday. Still, the swarm has surpassed Mount Rainier's last large one in 2009 'in terms of magnitude, total events, event rate, and energy release,' the USGS said in a status report Thursday. Mount Rainier is viewed as 'potentially the most dangerous volcano in the Cascade Range' due, in part, to its frequent earthquakes, according to the USGS. In ordinary times, Mount Rainier sees an average of nine quakes per month and swarms once or twice every year. Only Mount St. Helens has more temblors in the Cascade Range. Seismic activity is different in all volcanoes, and researchers are unsure why, Iezzi said. The recent earthquakes have presented researchers with new opportunities to learn more about Mount Rainier, which Iezzi called 'exciting,' even as their magnitudes have been small enough to go undetected by the public. 'Even if you were standing on Mount Rainier,' Iezzi said, 'you wouldn't be able to feel these.' Researchers currently hypothesize that the swarm, as others have been in the past, can be attributed to hydrothermal fluids — very hot water and gases deep in the volcano — moving through preexisting faults beneath the mountain. While earthquakes can cause volcanic eruptions, there has been no evidence of a correlation in the Cascades, and researchers have not seen any troubling signs during the swarm, according to Iezzi. Such warnings would include magma moving from the depth toward the surface, rockfalls and quakes increasing in size or becoming more shallow, she said. On its webpage about general Mount Rainier earthquake hazards, the USGS noted that quakes could trigger landslides, leading to volcanic mudflows, known as lahars, which could be dangerous to surrounding valleys. The agency said that the recent earthquakes are too small to pose a significant threat to hikers. A recent increase in rockfall and icefall at Mount Rainier has been attributed to warm temperatures unrelated to the swarm, it said. As of Friday morning, the Cascades Volcano Observatory and Pacific Northwest Seismic Network have located 391 earthquakes since the swarm's beginning and identified many others that it could not locate, according to the USGS. A quake can be detected by data, but it needs to be big enough and identified by enough seismometers to be pinpointed, Iezzi said. The earthquakes were between 1.5 and 4 miles in depth, with the largest being a 2.3 magnitude on Tuesday afternoon, the USGS said Friday. After being detected at rates up to several per minute when the swarm began, quakes were occurring three days later at a much slower rate. Researchers officially located 30 earthquakes per hour at the swarm's peak Tuesday but that figure had dwindled to a few per hour by Friday. By comparison, researchers in 2009 located 120 earthquakes at Mount Rainier during a three-day swarm — the largest being a 2.3 magnitude — although more than 1,000 quakes were detected, the USGS said. A 3.9-magnitude earthquake documented beneath Mountain Rainier in 1973 is the largest on record at the volcano, according to the agency. Iezzi said it was unclear when the current swarm would come to an end, a conclusion that researchers will reach when Mount Rainier returns to normal seismic activity. When the swarm began, the USGS said it likely would continue for several days and that most swarms at the volcano last less than a week. 'If the swarm lasts more than a week or so, that would be different than the last large swarm at Rainier in 2009,' the agency said in a statement Tuesday. For Iezzi, the swarm has served as 'a good reminder' that Mount Rainier is an active volcano, and she encouraged the public to keep aware of information distributed by the USGS. 'These are active systems,' she said, 'so we're constantly monitoring all the volcanoes in the Cascades.'
Daily Mail
09-07-2025
- Science
- Daily Mail
Dangerous US volcano 'is still active' as scientists reveal troubling source behind hundreds of earthquakes
More than 400 earthquakes rattled Washington's Mount Rainier over just 12 hours on Tuesday, sparking fears that the catastrophic volcano could soon erupt. The US Geological Survey (USGS) issued an update at 1:00pm PT, reminding the public that Rainier is far from extinct, but 'is still active.' This huge, stratovolcano looms over nearly 90,000 people living in cities such as Seattle, Tacoma, and Yakima in Washington as well as Portland, Oregon. Even though Rainier has not produced a significant eruption in more than 1,000 years, this weeks swarm of earthquakes caught the attention of the USGS as such events are often associated with volcanic unrest. A USGS geophysicist clarified that the current tremors at Rainier are not being driven by rising magma, but are likely the result of hot fluids. Alex Iezzi explained that hot water is probably circulating through pre-existing fractures in the rock beneath the surface, which can generate small, frequent earthquakes as the pressurized fluids cause the surrounding rock to shift and crack. However, Rainier is still closely monitored, as changes in these fluid-driven systems can sometimes precede more serious volcanic activity. A network of webcams, seismometers, GPS stations and infrasound sensors at the volcano are watching it around the clock, looking for any changes that signal an eruption. Volcanologists have said that it is only a matter of time until Rainier, arguably the most dangerous volcano in the US, unleashes on the Pacific Northwest. 'Mount Rainier keeps me up at night because it poses such a great threat to the surrounding communities,' Jess Phoenix, a volcanologist and ambassador for the Union of Concerned Scientists told CNN. But for now, the USGS has found 'no indication that the level of earthquake activity is cause for concern, and the alert level and color code for Mount Rainier remain at GREEN / NORMAL.' Tuesday's earthquakes were very small, measuring up to a 1.6 magnitude. 'Earthquakes are too small to be felt at the surface and will likely continue for several days. There would be no damage caused by such small events,' the USGS said. The Pacific Northwest Seismic Network, which monitors seismic activity in the area, detected 25 earthquakes as of 11:20am PT, with a magnitude 2.3 as the strongest. However, this is the largest swarm of earthquakes since 2009 that saw over 1,000 tremors. The volcano typically experiences a rate of about nine earthquakes per month and swarms every one to two years. 'Earthquakes are one of several parameters we monitor to indicate what a volcano is doing,' said the USGS. 'Right now, this swarm is still within what we consider normal background levels of activity at Mount Rainier.' The USGS Cascades Volcano Observatory (CVO) added: 'Instruments do not show any detectable ground deformation at the volcano, and no anomalous signals have been seen on the infrasound monitoring stations.' When this volcano eventually blows, it won't be lava flows or choking clouds of ash that threaten surrounding cities, but the lahars: violent, fast-moving mudflows that can tear across entire communities in a matter of minutes. Large lahars can crush, abrade, bury, or carry away almost anything in their paths, according to the US Geological Survey (USGS). 'Tacoma and South Seattle are built on 100-foot-thick ancient mudflows from eruptions of Mount Rainier,' Phoenix said. This is a strong indication that these populous cities lie within the path of potential lahars generated by a future eruption. Volcanic eruptions usually cause lahars by rapidly melting snow and ice that covers the volcano's slopes, which then destabilizes loose dirt, rock and volcanic debris and causes it to flow rapidly downward. But it doesn't always take an eruption to trigger a lahar, according to the Seismological Society of America. Rarely, these powerful mudslides can form as the result of gradual weakening of the volcano's slopes due to past eruptions, or heavy rainfall after an eruption. The deadliest lahar in recent history resulted from a 1985 eruption of the Nevado del Ruiz stratovolcano in Tolima, Columbia. Within hours of the eruption, a torrent of mud, melted snow and rock inundated the town of Armero and killed an estimated 25,000 people. This event, now known as the Armero tragedy, was the costliest volcanic disaster in history, according to The International Disaster Database. The total economic impact was estimated at $1 billion. The 1980 eruption of Mount Saint Helens, located in Washington just 50 miles from Mount Rainier, also produced a dangerous lahar that destroyed more than 200 homes, over 185 miles of roads and contributed to the total death toll of 57 people.
