Aftershocks following a significant earthquake, such as a 7.1 magnitude event, can continue for days, weeks, months, or even years, though their intensity diminishes over time. Most Washington State residents don’t notice aftershocks unless they are over 4.0. California had a major earthquake yesterday, and over the last 24 hours, they have had hundreds of aftershocks ranging from 1.0 upwards to 4 or so in range.
Here’s a general idea of their behavior
Immediate Aftershock Sequencemost significant (First Few Days to Weeks)Weeks to MonthsLong-Term Aftershocks
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- The most intense aftershocks usually occur within the first few hours to days after the main earthquake.
- The most significant aftershocks tend to occur within the first 24 to 72 hours, although smaller ones may continue for weeks.
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- Aftershocks gradually become less frequent and less powerful as time passes.
- While significant aftershocks may still occur over the next several months, they typically decrease in frequency and magnitude.
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- Aftershocks can still occur for months or even years after a major quake, though by this point, they are usually smaller and less frequent.
- The aftershock sequence can last up to a year or more, but these quakes’ overall frequency and magnitude will diminish.