When you buy through links on our site , we may earn an affiliate commission . Here ’s how it works .
The Seattle region may have been slay with a massive , magnitude 7.8earthquake1,100 years ago after a series of hidden faults ruptured simultaneously , a new study suggests . That is much more powerful than current warnings propose is possible from the same geological fault zones .
researcher have be intimate for a foresightful clip that Puget Sound , an area that contains Seattle , Tacoma and Olympia , was rocked by massive quakes in the past . geologic evidence evoke these tremblers rumbled sometime between 900 and 930 A.D. and had magnitude in the low 7s . The current best guess is that there were at least two major quakes during this time , one result from the Seattle Fault Zone ( SFZ ) , located beneath and around the city , and another from the Saddle Mountain Fault Zone ( SMFZ ) in southwest Washington .
The area surrounding what is now Seattle was rocked by a massive earthquake around 1,100 years ago.
But in a new study published Sept. 27 in the journalScience betterment , researchers examine the fossilized remains of trees stamp out by the quakes and found that each demerit zona likely bust at the same time , or at least within a very short blank of time of one another . If the zones did give way asunder at the same time , the resulting earthquake would have been more hefty than any other past simulation has augur .
This could have big implications for the 4 million mass presently subsist in Puget Sound , research worker wrote . Current warning models should be update to calculate for a likewise powerful temblor hitting in the future , they added .
Related : How big is the largest potential seism ?
Researchers pulled up sections of fossilized tree stumps from the floor of Price Lake near Seattle.
In the report , the researchers analyzed fossilise Douglas fir ( Pseudotsuga menziesii ) trees from six sites across Puget Sound . The team estimated when the trees died by combining tree ring tally and radiocarbon dating . The Sir Herbert Beerbohm Tree in the SFZ and SMFZ likely die within a six - calendar month point , sometime between 923 and 924 A.D. , the depth psychology found .
This timeframe suggests that the quake were due to the sametectonic platemovements , increasing the likeliness that they occurred simultaneously . If they did not , then the investigator surmise that each individual earthquake would have had a magnitude somewhere between 7.3 and 7.5 .
This may not seem too much weak than the likely 7.8 order of magnitude temblor — but earthquake are measure on a logarithmic scale , think that a magnitude 8 is 10 times more powerful than a order of magnitude 7 , and so away .
The SFZ and SMFZ are both very shallow , which intend they can be very destructive , similar to the demerit lines responsible for thedevastating earthquake in Turkey and Syriain February .
Related : The 20 largest record quake in history
A simultaneous rift would likely have do the most powerful quake the region ’s faults are capable of producing , the researchers wrote . If both zones were to simultaneously rupture again then there is every chance that it could be repeated , they tally .
— Predicting earthquakes is currently impossible . GPS datum could help change that .
— Dino - killing asteroid triggered ' mega - temblor ' that rocked the planet for month
— deep earthquake ever detected should have been insufferable
This is not the only discovery about the Puget Sound fault zone to emerge this yr . In March , researchers from the disaster modeling companyTemblordiscovered evidence on Bainbridge Island near Seattle that suggest a major quake could have bump off Puget Sound as recently as around 200 yr ago , although it ’s unclear how powerful it was .
However , despite the new determination , the most dangerous seismic terror to Seattle is the Cascadia Subduction Zone ( CSZ ) , a massive demerit line that stretches roughly 620 miles ( 1,000 kilometers ) from Vancouver Island , Canada , to Northern California . The CSZ is capable of producing earthquakes with a order of magnitude of around 9 , such as " the big one " that rocked the Pacific Northwest in the year 1700 .
' This is a very big earthquake ' : The science behind Myanmar ’s magnitude 7.7 seism
Creepy ' ghost lanterns ' in South Carolina are not what they seem , study suggests
The unvarying surveillance of innovative lifespan could exacerbate our brain function in ways we do n’t amply understand , disturbing studies suggest
