What we need to remember is that, while there certainly are areas of the globe where earthquakes are far more frequent, there is no such thing as a NON-seismic area on our planet. Some areas are LESS active but this doesn't mean they can't or won't produce earthquakes!
Memphis resident here. I'm fully aware of the New Madrid fault and the dangers it presents. Reelfoot lake is very visible proof how big this fault can be.
Thank you for making this video. I appreciate the effort to spread awareness. This video should be used by science teachers throughout the US. I've been in multiple earthquakes, both in CA and GA. CA is far better prepared for earthquakes than GA but GA has a couple potentially destructive fault lines that Georgians seem to know nothing about.
Some info in regards to Montana's largest earthquake (The 1959 Hebgen Lake earthquake), is that one of the landslides that was triggered by the earthquake tragically killed around 28 people in a popular camping site close to the epicenter. This quake also struck in the middle of the night (11:37 PM).
Thanks as always, Geology Hub! As others have said, this is a brilliant reminder that our planet is very geologically active, even in areas not associated with that kind of activity.
It's misrepresentative to say the 1700 9.0 earthquake was Oregon's largest but not also Washington's largest, considering that it broke the entire Cascadia megathrust fault offshore of both states (and well into BC). It should count for both states.
I was 4 years old when the 1983 6.9 earthquake in Idaho happened. It happened at around 6:30am when I was still sleeping so I don't remember it. My dad saw some of our neighbor's animals acting strange. A few minutes later, he heard the closet doors rattling, so he thought I was playing in the closet. Then he saw a hanging light swinging and he felt the shaking. I wish I was awake so I could remember it.
5:42 Might be interesting to have dedicated videos going into the hotspots on this: - What's with the inland arc of highest hazard in Alaska? - What's behind the higher hazards in Oklahoma, eastern Tennessee, South Carolina, and along the Canadian-New England border?
The Oklahoma area is probably related to proximity to the New Madrid system (which was a failed rift zone that didn't split the continent, but has related elements running from south of the Great Lakes down to the Gulf (but the New Madrid system is just one segment of it - Illinois' earthquake could be on a neighboring fault system, and there's been arguments that the overlapping active areas should be considered one, much how there's debate on the relationships between San Andreas and Cascadia triggering each other). The rest are all probably from faults left over from the formation of the ancient Appalachians, which used to be much wider, and as tall or taller than today's Himalayas. Most of the sedimentary rock on either side of the current mountains are actually hundreds of millions of years of compacted erosional sediments from those mountains, or the sealife (limestone) or swamps (coal) that grew on the accumulated sediment.
The inland arc of hazard in AK is the Denali fault. Massive strike-slip system. I was in the interior when part of the fault ruptured in 2002 as an M7.9. It was the first large quake I was able to experience.
Anyone who's lived in Charleston knows about the 1886 earthquake and a lot of the old brick homes in the historic district have earthquake bolts on them.
I grew up a couple hours from Charleston and learned of the historic quake at a young age. The earthquake bolts on houses in the downtown area are often covered with ornamentals which can be floral in design, or a mask like a gargoyle.
It is determined by the greatest amount of offset the geological features underwent during the earthquake, taking into consideration the composition of the geological features affected. It's math. I'm a sedimentary geologist, but a structural geologist could explain in greater detail.
They're not mentioned in this video because they're not the strongest earthquakes in those states. Living in Middle TN, most of the quakes I've ever felt have indeed been from the East out around the Smokies, but those are thankfully nothing at all like the ones from the NMSZ in West TN. The ones I've felt or heard of others nearby feeling have been mostly magnitude 3-4 or so. Whereas our state's strongest historical earthquake was a 7.7 that rang bells 900+ miles away in the Northeast!
Thank you for this video! My family and I experienced a minor earthquake in Maine in 1971 or so, probably no more than a magnitude 5, and I have experienced a few in Virginia, the most recent being the one in 2011 you mentioned, which is the strongest I have felt in my lifetime. Earthquakes in New England are thought to be glacial rebound quakes in origin, which I wish you would do a video on, as Sweden experiences those too. I have read about the New Madrid and Charleston quakes, but was surprised to learn just how strong the Charleston quake was and what caused it. I have been fascinated to learn how common earthquakes really are and the plethora of faults even in large continents.
The Virginia quake is the only one that I've ever experienced. I was at work, in W.Va., 250 or more kilometers northwest of the epicenter. I had drawings spread out on a large wooden table in a large central room on the second floor of the office building. I was concentrating on a drawing when the table shook. I figured it was a co-worker walking by and purposely bumping the table to annoy me. I didn't look up until it shook a second time, and was surprised that whoever it was had disappeared so quickly. Then the guy in the office next to mine started hollering because he saw pictures on his office wall shaking. At the time, I was fearing that a large explosion had happened somewhere near, despite the fact that there was no sound.
I’ve got a general earthquake related question. Do you know of any geologists that are focused on Mexico? I relocated from my native California to the state of Guanajuato in Mexico, and I appreciate the coverage you’ve given to Mexico’s volcanic activity. I prefer my science in English, but I can muddle by in Spanish. I’m mostly curious, but I must admit that I’m concerned by the lack of perceptible seismic activity. I’ve lived in both Southern and Northern California and I’ve experienced the major quakes there over for over 50 years. I’m kind of freaked out that I haven’t been through an earthquake for over a dozen years. 😅
I'm no expert but it looks like most of Mexico's major earthquake activity is along the west coast, maybe 200 km west of you. Mexico City itself takes pretty bad damage from earthquakes that far away due to the dried lake bed it's built on, but anything else that far inland shouldn't get shaken up too much.
I was told that the area of Guanajuato sits on bedrock, which absorbs the earthquake waves, which means you don't feel them there. I honestly don't know how accurate that really is, but family down there have never felt an earthquake- even that big one in the 80's. 🤷♀️
The New Madrid Seismic Zone is what's likely to cause earthquakes where I live. Not that we're actually _near_ the New Madrid Seismic Zone, but... we're close enough. I believe the 7.2 to 8.2 magnitude earthquake in 1811 caused around 6.0 to 7.0 damage in the area I live? It's hard to say because this was before modern detection equipment. But there's also the fact that nothing around here is built to withstand earthquakes. Tornadoes? To a degree (as much as is reasonable anyway). Earthquakes? Not at all. Edit: Okay, I guess there was a more recent one of 5.1 in SE Iowa. Even so, I think the New Madrid Seismic Zone is still where the biggest threat of earthquakes is for our region.
1:36 The largest quake in Florida's history occured in 1780 in Escambia or Santa Rosa county in the Bahamas fracture seismic zone. This Earthquake is estimated to have been magnitude 6.0. As recently as 1997 there was an Earthquake centered either in Escambia county, Fl or Escambia county, AL (right along the border) which registered as a 4.9
They used recorded intensity from written accounts to estimate the Richter magnitude. Even now there are minor differences in different magnitude algorithms. The Earth is very complex and instruments all have scientific uncertainties.
Woah! Kentucky is VERY MUCH in the zone of impact of the New Madrid quakes. I had an ancestor in Western KY who broke his leg on the CEILING of his cabin when thrown out of bed in 1812! If 100km offshore counts, then literally IN THE BOARDERING RIVER certainly counts, also.
Hey, I recognize all those 1994 Northridge clips! Great and very succinct reminder for folks who don't necessarily live in "quake country" that there's no such thing as a truly quake-free place; and those places I feel are the ones in the greatest danger. Unlike those of us in "quake country" with our extensive past experience dealing with them and improving our buildings to withstand them, their buildings may not be built anywhere close to that standard. I mean, if the New Madrid pops off just one 7.0 or thereabouts much less another sequence of them, the damage is going to be massive AND widespread given quake motion in the eastern half of the US seems like it travels a hell of a lot further than similar motion in the busted-up mess of rock units that make up the western end of the continent.
3:02 There are places in Virginia, DC and Maryland that are still being repaired after the 2011 quake. oddly enough, I've been all over the West Coast, but the one quake I felt was that 2011 quake in Virginia
It is interesting that Michigan's 1905 quake was in the upper peninsula but has the lowest risk of earthquakes compared to the lower peninsula. I understand this is an approximation. Also, USGS shows multiple earthquakes happening in Texas the past few months, so I am also surprised Texas is blue/white on the final State Map graph that shows highest hazard to lowest hazard. Does the multiple earthquakes happening around Toyah, Texas effect this chart? I have no geology skills, a simple novice with curiosities. I appreciate your videos. Thank you for what you do! ~Amanda
Yeah when I first saw that map a few years back I was somewhat surprised as well the thing which makes it make more sense is that its measuring the risk to infrastructure property and people so a high Earthquake risk in a low populated area isn't going to be weighed as highly as a smaller quake in a more densely populated area.
I could be wrong, but I think the largest Michigan earthquake was a M4.6 near Coldwater in 1947. The only reason I know was because my grandfather lived in Kalamazoo at the time and he recalled how it shook their house and made lots of cracks in the walls and ceiling.
I knew of the NH earthquake, and quakes. I live in the state and it's one of those interesting facts I'll share about this state. Thank you for the video.
I live in California and I appreciate the earthquake resistant engineering that has been incorporated into our modern architecture over the years. We get some real shakers out here yet I rarely feel unsafe (with proper precautions). We've actually become pretty jaded as people don't seem to notice much under 4.5. Great video!👍
Its a random thing. I'm pretty sure a 4.0 struck in my town in the UK when I was little. Everyone remembers it but I couldn't find it reported anywhere. I'm pretty sure a 6.1 or 6.2 even happened just offshore in the North Sea in recent times
I remember about 1980 in eastern Maryland, I was in by neighbor Boyd's bedroom ,when we heard a rumble and his Doors poster rocked off the wall three inches and back. I also remember one in Westport Connecticut about 1970, it rattled the glass bottles in the kitchen window.
Washington had a 6.8 earthquake in 2001. "The deep M 6.8 earthquake centered in the Nisqually are near Tacoma was felt all over western Washington, from Oregon to British Columbia and Montana." (Take from the state's website) That is the strongest and most "recent" earthquake in Washington State.
2018 we had a 4.5 in east TN, with epicenter 5 miles from my house. I was laying in bed watching TV. I heard a noise like thunder, then the bed acted like an air mattress on the lake. Small compared to CA, but one I'll remember! 😮
That Virginia earthquake was felt all up and down the east coast. It was like a 4.0 in DC and Maryland. There’s video of government workers all running out of buildings (which is what you’re not supposed to do, but we’re from the midatlantic so we don’t know better). It shook the house and freaked out the cats. Almost knocked over my then boyfriend’s LCD tv until a roommate caught it. They’re STILL fixing the damage caused by it in DC. DC also had a tiny 2.3 earthquake this year. I didn’t feel it but I heard the rumble and thought it was a truck driving by. It sounded like the 2011 one. Like Oklahoma, it’s probably due to fracking.
The Dallas TX area had a series of earthquakes in the 2000s, most likely caused by fracking. I think I remember the most severe one was a 3.2, which I felt as a rocking motion that left cracks in several walls.
South Carolina beating out Washington was not expected, though I guess that's kind of on a technicality since the Cascadia quake of 1700 would have affected the whole region. The American east is weirdly geologically active for being a textbook example of a passive margin.
I remember the Pennsylvania earthquake. Even though I was five years old at the time, I remember being in my grandma's house and thinking "Was that just an earthquake?" My family dismissed me when I asked, but living 30mi from the epicenter, I'm fairly confident I would have felt a 5.2 lol
Note Oklahoma actually does have a seismic belt Which runs from the Texas panhandle through southern Oklahoma and northern text And it produced a magnitude 6.8-7.2 earthquake during the late Holocene so that along with the Nemaha Ridge fault are the reasons why Oklahoma’s seismic risk is so much higher then usual
I remember a report of an earthquake in Quebec City and long whileago. the news report showed the ankor saying "Voici une montaire" I now know how to say 'that's an earthquake in French.'
Here in Montana that devastating earthquake caused so many deaths due to the landslide that created Quake lake I’d say more powerful thrust then on the San Andreas fault to able to create a artificial lake imo
I’d like to know where you’re getting the information that ‘relatively few people in South Carolina’ know of the 1886 Charleston Earthquake. Earthquake Risk is part of standard risk assessment in the area. Earthquake Drills are standard in schools. The Lake Murray Dam had an entire Second Dam built behind it in case an earthquake caused liquefaction of the primary Earthen dam. Many they don’t know of the specific earthquake, but people here know a major earthquake is a risk.
It is a bit unfair to name the Cascadia quake of 1700 as Oregan. The fault starts just offshore of California and runs all the way to just shy of Alaska's borders. It was a full rupture event, meaning the entire length of the fault ruptures (this is true for this fault nearly every time it breaks) Meaning at least 3 states where directly adjacent to the quake. It deserves special mention for another reason as it is by far the single most deadly potential fault zone in the entirety of North American. Not the highest risk of a quake happening in any given year of course, but pure power it is more dangerous than even Alaska's fault zone.
The New Madrid Seismic Zone doesn't get as much attention as it deserves, but I'd still say that most of us at least here in TN are aware of it. I would assume the same for AR and MO. Thankfully, i live about 200 miles away from the Mississippi River, so damage here in Eastern Middle TN would be much lighter than the complete devastation in West TN, SEMO, Northeast AR, and Northwest MS, especially the areas near the river where the soil is basically sand. The accounts from people who witnessed the 1811/1812 quakes are crazy to read. Ground just randomly exploding into sand volcanos, along with soil liquefaction causing buildings to sink into the ground. There were even reports of portions of the Mississippi flowing backwards, though it is my understanding that scientists consider this likely to have been an illusion. Also, for what it's worth, New Madrid is not pronounced like the city in Spain after which it was named. It's MAH-drid, not ma-DRID (or ma-DREED.)
That sounds plausible, since the Lisbon quake was centered in the Atlantic. Plate movement could have reverberated across the ocean and triggered a secondary quake near Massachusetts.
I remember the Virginia 2011 earthquake. I was working in the lowest level of our Northern VA office building, and the banging sounds felt and sounded like a washing machine the size of a Volkswagon was spinning an unbalanced load of rocks on the floor right above us. People who were outside out the time said you could see the ground and parking lot rippling like small waves on a pond. We were about 80 miles or so from the epicenter. Also, never would have guessed my home state of PA had a 5.2, I thought I was being generous guessing 4.5 max.
That was interesting the Oregon had a 9.0 quake. Like your earthquake hazard map. I was living in Anchorage during Alaska Quake. We had a lot of liquefaction problems sitting on a lot of glacial clay.
I was in Charleston 1991 ish for a 4.5 earthquake that "rolled the concrete floor like a wave" going through it blew my mind! looked like the cartoon when Tom chasing Jerry the mouse under the carpet how the carpet made a wave just like that but in concrete! One brick building came down. I think they call it the S wave. Secondary wave.
Thanks for this list,, I live in Virginia and locals warned when I moved here that there are small earthquakes now and then, tho they are usually small and sometimes centered in West Virginia, still felt here in South West VA.. Add to that we get tornadoes ever few years in this area, tho larger and more frequently the eastern side of the state has them, well... Sill I take this place over California and the endless slipping and shaking in the Central Coast any day!
@@MatthewChenault I am FAR inland, luckily. Ian battered us as a normal storm, but I am in the Appalachians, not the coast, so hurricanes tend to be weakened really badly by the time they get to my area.
@@MatthewChenault I am in the SW tip of VA, I can almost toss a football into NC, TN, and with a short trip KY. Hurricanes are deently weakened when they get to my area. Ian for instance was just a windy storm making it rain after kicking SC around for a while, lol. I'd rather have high winds than tornadoes, and wee little quakes than the endless rumbling I lived with for decades in Cali.
I have lived in both western and eastern Virginia in the past 40 years, but have only felt a few quakes here in eastern Virginia in that time. A magnitude 4.5 struck on the same fault a number of years before the 5.8 in 2011, which as he pointed out in this video is the strongest one recorded here. I think the "Fall Line" that divides Piedmont from Tidewater is actually an upthrust fault, but it would be great if GeologyHub did a video on this.
Hi Geology Hub narrater! "Madrid" in New Madrid, Missouri is pronounced "Mah'-drid". The "a" is a wide short 'a'- sound and the accent is on the first syllable. Although named after Madrid, Spain, it is pronounced differently by the locals. Local pronunciation becomes correct locally. Like Lafayette, Louisiana is pronounced like the French name it is with the accent on the first syllable (La' fay-et). However, Lafayette County, Mississippi is pronounced "La-fay'-et". Accent on "fay". And that's correct there.
please do a video about the canadian shield and little known similar to sanadreas faultline running accross a marshland area. which we had bog people rise up from out of the marshland, that were mummified like pompeii, Ottawas faultline is the seismic zone area I'd love to hear more about we used to have hot springs in carlsbad springs and theyve apparently come back recently
The middle of the USA along the Mississipi has a deep fault section(eta New Madrid Faultline) an earthquakes happened but not regularly more per century than everyday along coasts
I would like to see you do the same with all of the countries in the world, since there might be countries which people don't associate with earthquakes that might have produced destructive earthquakes.
The earthquake that struck Virginia in 2011 struck around the town of Mineral, just east of Louisa Courthouse. The epicenter was less than ten miles from the North Anna Nuclear Power station nearby the Lake Anna reservoir.
Yes, and the North Anna station survived the earthquake just fine, because the US puts a LOT of work into the safety of its nuclear plants. Unlike Japan, where they build nuclear plants on top of tsunami deposits and then act shocked when the plant gets hit by another tsunami.
I was told the February 2001 earthquake in Washington State (the Nisqually quake) was a 6.9. I was in Seattle on the industrial waterfront at that time and remember the reports initially ranging from a 7.0 to a 6.8 and eventually the USGS said it was a 6.9
When you go to college and take Physical Science, you learn about these earthquakes. Depending on the professor. Ohio has them too. I heard OH has 1200 faults that lie beneath the state. True? Our quakes here in the east are felt much farther and are much more destructive than the ones out west because of our soil and rock composition.
The 1700 should be Washington state and Oregon. For starters the quake damage Washington more than Oregon. The vault zone also fuels the cascade volcanoes that are mostly in Washington
MIssouri is going to be so messed up when next one hits. Not in just structure damage...but the mississippi river is going to flood so much land. You can still see on google maps places that it changed direction from last time.
How were the pre 19th century magnitudes determined? I see there were variations of seismographs going back 1000 years. Care to elaborate on any of those time periods?
Two years ago we we were feeling/hearing small earthquakes in mid SC every few months -- it was bizarre! We still get them here and there but not as often. The epicenter is in Elgin, SC. People who grew up here know about the 1886 Charleston earthquake -- it was one of three major events that destroyed the city (the other two being a great fire and the Civil War). Intraplate earthquakes are quite interesting.
Even though I live in Delaware, I felt the 5.8M earthquake all the way from Virginia. I remember sitting at my brother's desk on his computer playing a game, when I noticed his chair wobbling back and forth. I wasn't thinking much of anything at all as I felt it, but I reached to our TV to keep it from toppling over. By far the _strangest_ day ever!
