STATE
Earthquakes rattle Valencia, Socorro counties again
Small quakes measuring magnitude 3.1 and 2.5 have struck near the Socorro magma body, a pattern seismologists say is cyclical and not unprecedented
Another swarm of small earthquakes is shaking southern Valencia and northern Socorro counties.
At about 9:40 p.m. Monday, a magnitude 3.1 quake was detected about 9 miles west-southwest of the Pueblitos area in northern Socorro County.
A second small quake, magnitude 2.5, was recorded around midnight Monday about 14 miles west of Pueblitos, this time just north of the Valencia County line.
In June, a series of six earthquakes 鈥 the strongest of which measured magnitude 3.9 near Las Nutrias 鈥 had residents wondering just what was happening.
The small quakes and swarms are a familiar pattern to seismologists who have studied the area for decades.
Mairi Litherland, seismic network manager with the U.S. Geological Survey鈥檚 Albuquerque Seismological Laboratory, said the swarms occur over the Socorro magma body.
鈥淭his area has been monitored for a long time, starting about 1960. The network has changed some since then, so we have the ability to detect small earthquakes people can鈥檛 feel,鈥 Litherland said. 鈥淭hose that people can feel, we鈥檝e had the ability to detect the whole time.
鈥淲hat does happen in this area near the Socorro magma body, the pattern we鈥檙e seeing, is there鈥檚 a swarm that lasts a couple of days or weeks, then it quiets down, then there鈥檚 another one. It鈥檚 a very common pattern for this body that we鈥檝e seen happen in the historical past. So, it鈥檚 not your imagination that you didn鈥檛 feel anything a couple of years ago and now you鈥檙e feeling something, but it鈥檚 not unprecedented.鈥
There were a series of small earthquake swarms in the area in 1990 and 1991, but it has been fairly quiet in recent years. Litherland noted that in seismology, it is difficult to be absolutely certain when earthquakes will occur or how severe they will be, but the current activity is similar to what has happened in the past.
鈥淲e see when earthquakes happen and that helps us map faults and, in a statistical sense, understand what鈥檚 happening,鈥 she said. 鈥淪tress is building up due to the magma body and then it releases. We can鈥檛 say when they will happen or how big, but people are correct 鈥 there are more this year than typical. In 1990, there were also a lot more than typical. It goes in cycles.鈥
The patterns seen with these swarms are typical of magma bodies, Litherland said. In other locations, earthquakes are the result of the Earth鈥檚 crust moving along plates and faults.
鈥淚t鈥檚 a little different here. The cause is the magma body, not plate tectonics, but it鈥檚 all related,鈥 she said. 鈥淚f you think about the typical pattern, there鈥檚 a big quake and aftershocks. With a magma body, you see several earthquakes that are relatively the same size over time.鈥
Scientists don鈥檛 have a perfect understanding of how magma bodies cause quakes, but they appear to be related to fluids and other properties unique to a magma body.
In her June interview with the 近距离内射合集-Bulletin, Litherland noted that while oil and gas regions in the state have seen an uptick in human-induced quakes, the Socorro area has a long, well-documented natural history of seismicity.
Neither of the earthquakes felt this week was as large as the initial quake in June, which topped out at magnitude 3.9.
鈥淎 lot of people felt it. It鈥檚 possible there will be more felt earthquakes in this swarm,鈥 she said. 鈥淚 do encourage anyone who felt the quakes to report them to the USGS 鈥楧id You Feel It?鈥 website. It helps us understand the impacts they are having on people.
鈥淭here is a lot of information on the website about earthquake preparedness. Historically, they have been moderate and not caused damage, but it never hurts to be prepared.鈥
If you think you felt an earthquake, visit to report the activity.
The 近距离内射合集-Bulletin is a sister newspaper of the Journal.