Profile picture
IRIS Earthquake Sci @IRIS_EPO
, 9 tweets, 6 min read Read on Twitter
M 4.4 - 11km NNE of Decatur, Tennessee earthquake.usgs.gov/earthquakes/ev…
These colored lines show the intensity of ground shaking from the #earthquake. How hard the ground shakes is related to the magnitude of event, the distance from the event and the local geology earthquake.usgs.gov/earthquakes/ev…
So far, 6000+ people have reported feeling this #earthquake via the @USGS. Did you feel it? Let them know 👉 earthquake.usgs.gov/earthquakes/ev…
Why was this (relatively small) #earthquake felt over such a large area when larger earthquakes on the west coast are felt over smaller areas? It’s because of the geology. usgs.gov/news/east-vs-w… @USGS
The east coast has thick sediment and old, cold, dense rocks which allow the seismic waves to travel further and thus be felt over larger areas. While the west has more earthquakes the crust there is broken & fractured.
Additionally, infrastructure on the east coast & in the Midwest isn’t built to withstand seismic shaking. This highlights the different between #hazard and #risk. Risk occurs when a vulnerable systems encounters a hazard. pubs.usgs.gov/fs/2011/3008/f… @USGS
If you feel earthquake shaking remember to “Drop, Cover and Hold On”. Here is additional information from @CentUS_ShakeOut earthquakecountry.org/library/ShakeO…
To learn more about the magnitude of an earthquake and the shaking that we feel check out this cool video on our YouTube Channel (snippet below).
@threadreaderapp unroll
Missing some Tweet in this thread?
You can try to force a refresh.

Like this thread? Get email updates or save it to PDF!

Subscribe to IRIS Earthquake Sci
Profile picture

Get real-time email alerts when new unrolls are available from this author!

This content may be removed anytime!

Twitter may remove this content at anytime, convert it as a PDF, save and print for later use!

Try unrolling a thread yourself!

how to unroll video

1) Follow Thread Reader App on Twitter so you can easily mention us!

2) Go to a Twitter thread (series of Tweets by the same owner) and mention us with a keyword "unroll" @threadreaderapp unroll

You can practice here first or read more on our help page!

Related hashtags

#earthquake #hazard #risk

More from @IRIS_EPO see all

Profile picture
We’ve had a lot of questions concerning the recent ground motion animations and the locations of our seismic instruments. The instruments shown in this awesome animation are from a special project called USArray. (usarray.org) THREAD
USArray is part of the @EarthScopeInfo project (earthscope.org), an @NSF funded project to study the structure and evolution of the North American continent.
USArray consists of 4 observatories: the Transportable Array (TA), the Flexible Array (FA), the reference network and the Magnetotelluric Array (MA). You can read about all of these in more detail at usarray.org. We’re going to focus on the TA.
Read 21 tweets
Profile picture
As both @seismo_steve and @janinekrippner have pointed out seismologists (or animals, or anyone else) can't predict earthquakes. usgs.gov/faqs/can-you-p…
However, we can give probabilities and forecasts of when earthquakes are likely to occur. This is not the same as prediction. usgs.gov/faqs/are-earth…
Many many seismologists, geologists and other scientists and communicators are working to develop these forecasts so that we can give the very best, most accurate information to the public, emergency responders and gov officials so that we can be prepared. scec.org/ucerf
Read 8 tweets

Related threads

Profile picture
(1) #Earthquake near #Anchorage, Alaska in the last hour.

Moderately deep & strong, expect some damage, but loss of life unlikely. Magnitude is usually downgraded from initial level.

Best info source:

earthquake.usgs.gov/earthquakes/ev…
(3) Some photos from around Anchorage that I've seen on Twitter. In New Zealand we have an earthquake of this type about once or twice a year. It is scary, but thankfully little damage is done.

#DropCoverHold is the best advice. More: ready.gov/earthquake
(4) If you feel an earthquake when you're on a beach or within a few miles of the coast, be aware of #tsunami risk.

"If it's long or strong, get gone." There is no time for warning sirens or messages.

If you don't feel it, that means any tsunami is hours away. You have time.
Read 36 tweets
Profile picture
Good morning from a UK with slightly less dull weather! I want to discuss two topics which are often confused & misunderstood, but first I wanted to clarify a few things from yesterday's threads #earthquake #Stress #faults 1/n
Referring back to the block diagram for dip-slip faults from yesterday, @CriticalStress_ noted that the stress arrows at the top were wrong. All faults have a confining (inward) compressional stress, but stresses from other directions can be larger 2/n
This diagram from @SEELeeds shows that in the example block diagram I gave the smallest stress (sigma-3, min) is inward perpendicular to the fault. The primary stress - the largest amount of force acting on the rock to produce a normal fault - is vertical: GRAVITY! 3/n
Read 31 tweets
Profile picture
(1) I will look into the details of this earthquake, since depth and location affect how much damage it did.

The last thing the starving, oppressed people of Venezuela need is a major earthquake.
(2) The first reports of an earthquake's magnitude always gets downgraded about 15-20 minutes later. Currently this one looks to be about 6.8.

Crucially, it's quite deep, at 76 miles (123km).

The USGS website model estimates 10-100 deaths & USD $10 million to $100 million.
(3) If this had been a shallow earthquake, the carnage would be massive. Thankfully it was deep.

There will be many aftershocks. People will be very afraid.

Here's the USGS impact modelling:
earthquake.usgs.gov/earthquakes/ev…
Read 4 tweets
Profile picture
Shallow M7.2 #quake strikes north of Lombok, #Indonesia, according to @USGS.
M7.0, according to #Indonesia government agency. bmkg.go.id/warning.bmkg
Revised to M6.9 by @USGS after seismologist review. earthquake.usgs.gov/earthquakes/ev… #Lombok #Indonesia #quake
Read 3 tweets
Profile picture
USGS | M 4.4 tonight 7km NE of Aguanga, CA In the pluton between Elsinore an San Jacinto faults. Thousands of tiny quakes have been occurring here for 2 years. earthquake.usgs.gov/earthquakes/ev…
Magnitude is controlled by the area of fault that moves in a quake. These tiny quakes near Cahuilla are moving very small areas and release only a small amount of strain. Caltech's Hauksson has looked for and not found evidence for associated fluid motion.
Many areas have swarms of small quakes. Sierra Nevada, Imperial Valley, Owens Valley but usually shorter duration. Oregon-Nevada border region had a long swarm 2014-15. This Cahuilla swarm is longest duration in SoCal since we've been able to see small quakes (since 1980)
Read 3 tweets
Profile picture
#Quake shakes Mexico City.
Prelim M5.7.
Read 7 tweets

Trending hashtags

#northridge #COLORADO #SecondDisaster #MASSACHUSETTS #Midterms2018 #show #TimesUp #bribery #Anons #hurricanes #MISSOURI #WVUfootball #JesusIsComingSoon #Qunts #featured #AnchorageEarthquake #DistrictofColumbia #Love #Nephilim #Tennessee #tsunami #Ohio #PollWatcher #Mountaineers #NORTH

Did Thread Reader help you today?

Support us! We are indie developers!

This site is made by just three indie developers on a laptop doing marketing, support and development! Read more about the story.

Become a Premium Member and get exclusive features!

Premium member ($30.00/year)

Too expensive? Make a small donation by buying us coffee ($5) or help with server cost ($10)

Donate via Paypal Become our Patreon

Thank you for your support!