California enormo-quake prediction: Cracks form between US boffins NASA and the US Geological Survey (USGS) experts are arguing over the likelihood of a major earthquake hitting southern California in the near future. The debate began earlier this week when eggheads at NASA's Jet Propulsion Laboratory (JPL) posted a study suggesting that the chances of an earthquake magnitude five or greater …
> "California will have earthquakes in the near future. "
You got that right. I grew up in an LA suburb, and I can attest that anyone who lives around LA for more than a few years will become quite familiar with quakes. In 1971 I was shaken out of bed by a 6.7 roller with the epicenter only 10 miles away. I've experienced three more since then, one felt at a distance of 300 miles, which slightly injured my mother who was close to it.
A threat of a mere 5.0 is normally not that scary to Angelenos. Nearly every structure is stick-built, and so can wobble a lot without collapsing. However, the La Habra area is old and full of unsafe buildings. It's also centrally located and much of it is on soft sediment that's prone to liquification. That area might not be much fun after a 5.0.
I live at the bottom end of the Pacific Ring of Fire, where we live with these things also. There were two 4-ish quakes this morning.
In 2011 we had a 6.7 in Christchurch, and they're still rebuilding (and will be for years and years).
The thing that worries me is the fact that Auckland is built on about 50 volcanoes, the youngest of which is only 600 years old. We are overdue for another forming, but there's not much point spending my life worrying about things that happen over geological time scales.
https://en.wikipedia.org/wiki/Rangitoto_Island
In 2011 we had a 6.7 in Christchurch, and they're still rebuilding (and will be for years and years).
Of course the magnitude of an earthquake doesn't tell you much about how much damage it will cause. Distance (depth and from the epicenter), ground composition, building construction, etc...
In the case of Christchurch, if memory serves, there were a lot of aftershocks and there was severe ground liquefaction. It's not surprising there was widespread destruction.
To quote the late great Yogi Berra "It's deja vu all over again"
Or would a "Back to the Future" reference be in order?
The US west coast is probably due a real big one (>7) in mid term so about 50 years. The only question is where it hits. Also, a real scary thought is the New Madrid fault along the Mississippi. It likes to let loose a whopper every few hundred years (last 1811/1812). The buildings in the New Madrid fault zone are not built to withstand a major shake (St Louis, Memphis)
The San Andreas can't provide much more than 7 because it moves too freely - and as has been pointed out, californians are pretty much prepared.
Cascadia on the other hand could easily be bigger than 8.5 when it goes, with the accompanying tsunami taking out most of the coastline between California and Vancouver Island. Populations in the pacific northwest are woefully unprepared.
New Madrid's last triple shudder were 8.1-8.3 apiece - powerful enough for the rollers to set church bells ringing in Boston. It's a long way from the centre of North America to the coast. It's about due to pop again and has the potential to destroy the USA as an economic power.
Today's news say that what is for dinner is pointless brinkmanship with Russia in Syria (I didn't get we have a manadate to unilaterally impose no-fly zones in Syria, but so a superpower has its rights), possibly followed by a fat nuclear exchange.
Better order a new "duck and cover" instruction set at amazon.
Although an earthquake of 5.5 can do significant damage such damage will be localized. It will certainly not be a 'end of world as we know it' event. Once you're into the sixes then things get interesting.
The Richter scale is exponential so 5 -> 6 -> 7 means changes of orders of magnitude in the amount of energy released. What that energy does depends on where the epicenter is and how deep it is.
(Incidentally, if you want a bit of end of world speculation.....I was in Romania earlier this year. Nice place but I was surprised on leaving to learn that the bit east of the Carpathians (that includes places like Bucharest and Ploesti) is as seismically active as California. You wouldn't have thought it from looking at the way houses are built and how stuff wasn't tied down inside them (you notice this sort of thing if you're a Californian). Since they seem to get a major quake every 30 years, regular as clockwork, they're a bit overdue for one about now.)
Of more interest is the big subduction fault off the coast of Oregon and Washington. That seems to let rip with an 8+ every 250 years or so, the last one being in the early 1700s before the Europeans arrived there... The subsequent tsunami is likely to flood everything west of I-5.
January 26, 1700 at 9 something in the evening, to be more precise. So -- middle of winter, at night.
Apparently the average time between the quakes here off BC and Washington is about 300 years. We're due. And it hasn't escaped me that every part of the Ring of Fire, NZ, Japan, Chile, California, has had one in the last decade or less. all but us.
I'm in Vancouver, living on a rocky hill and curious how this geology will react in a quake. I expect my house to slide downhill somewhat. Richmond, river delta at the mouth of the Fraser River, rich farmland in my childhood and now covered in homes, warehouses and even some highrises, is in big trouble.
Only 85% likelihood you say, not 99%. Well, nothing to worry about.
I remember seeing some ghost forest in Oregon that was killed by a Tsunami from the fault going up there. From 1700 - thats only 300 years ago and there was 2' of sand a couple of miles inland.
Hated having a Dad who showed you this shit rather than take you to Disneybollx but it stops you investing in sea side property!
The San Andreas is a strike-slip fault. It does not produce tsunamis.
The so-called "ghost forest" in Oregon was PROBABLY caused by a rather large hunk of one of the Hawai'ian Islands slipping into the Pacific, displacing a massive quantity of water.
Hey, East Coast ... Have you noticed that the Azores are quite likely to cause a similar issue, and fairly soon, at least in geological time?
When, not if.
The southern portions of the East Coast would likely be washed over quite far in but toward the north it would be more like Sandy with only the very coast taking the brunt of it as the terrain rises pretty quickly as you move inland.
Just think, if we get lucky Congress will be in session.
"The Ghost Forest was created by the land slipping down into the sea - most likely caused by local tectonic activity."
This is normal for subduction faults. Look at what happened in 1964 in Alaska. Some areas slumped by several metres during the quake as the land slipped back to "normal" position after decades of being compressed and uplifted by the pacific plate pushing under it.
"This is normal for subduction faults."
Unfortunately for your scenario, the subduction is UNDER North America, thus raising the coast-line. The tsunami (probably from a largish bit of Hawai'i slipping into the ocean) flooded out the low–lying forest on the Oregon Coast. The glaciers melting at the end of the last ice-age brought the water level up a trifle.
Oregon's Cascadia subduction zone fault system is not Alaska's, even though they are connected.
"Unfortunately for your scenario, the subduction is UNDER North America, thus raising the coast-line"
The coast line is pushed up and then chunks of it will slip down again - it's not a constant upwards movement only the long term average is up. Gravity is always acting on any rocks thrust upwards
I wasn't talking about the San Andreas, I was looking further north for the big quake and tsunami.
I think the Hayward Fault is building up to something in the near future (noting that 'near' in geological terms is a bit imprecise). San Ramon just had a quake swarm, and the Hayward itself has had a couple of little warm-up events. With the Napa quake relieving a bit of stress in the system to the north, it's got to be pretty tense down around the East Bay geology.
"I think the Hayward Fault is building up to something in the near future (noting that 'near' in geological terms is a bit imprecise). San Ramon just had a quake swarm, and the Hayward itself has had a couple of little warm-up events."
That little shit just rattles the nerves of people without a clue. In all honesty, it's actually a strain-relief, there will probably not be a major quake there any time soon.
"With the Napa quake relieving a bit of stress in the system to the north"
Actually, that was the "American Canyon" quake, news media notwithstanding.
" it's got to be pretty tense down around the East Bay geology."
Nah. That's all been slipping & relieving pressure for the last 40 years. The Rogers Creek fault hasn't shifted in about a hundred.
When, not if.
"The subsequent tsunami is likely to flood everything west of I-5."
If enough water gets past the very narrow Golden Gate and the couple of ranges between the coast and the central valley to even GET to I5, I rather suspect that even Auburn will get flooded out. Remember, I5 is in a rather flat valley. Its road-bed is no barrier to anything.
I remember a book written in the 70's by (I think) Alistair MacLean called Goodbye California. At one point there is a discussion about earthquakes in California (the book is set in that state) and one of the characters says (paraphrasing slightly here since I'm going by memory):
If our civilisation disappears and is replaced by another in a thousand years, then they will speak of Los Angeles in much the same way as we speak of Atlantis. It is not a case of if, but only a case when.
just because I think it's interesting:
"An Extraordinary and Surprising Agitation of the Waters, though without Any Perceptible Motion of the Earth, Having Been Observed in Various Parts of This Island, Both Maritime and Inland, on the Same Day, and Chiefly about the Time, That the More Violent Commotions of Both Earth and Waters so Extensively Affected Many Very Distant Parts of the Globe; The Following Accounts, Relating to the Former, Have Been Transmitted to the Society; In Which are Specified the Times and Places When and Where They Happened "
http://rstl.royalsocietypublishing.org/content/49/351
doi:10.1098/rstl.1755.0059
Nowadays they'd just say "OMG!" on twitter
The USGS exists for a reason.
As for:
"A 6.0 quake occurring last year in the San Francisco Bay Area's Napa region killed one person, injured about 200, trashed the area's vineyards, and shook tens of thousands of people out of bed over a wide distance."
The vineyards were not trashed. Not a one of them. At all. No grapes damaged. Really.
My take on that quake: http://forums.theregister.co.uk/forum/containing/2279808
The REAL "next big one" here in California will be on the Rogers Creek Fault, not a thousand yards from my left elbow as I type.
When, not if is the mantra around here. We think we are ready for it here at Chez jake. Only time will tell :-)
The dichotomy in opinion reflects the conflict between science and mysticism; something California experiences daily on a variety of topics. It could be the rampant substance abuse is my best guess. Building an advanced civilization upon a geologically unstable location has been going on since the Minoans. I wonder if they were on drugs too?
> "Building an advanced civilization upon a geologically unstable location has been going on since the Minoans."
I wonder if there's a connexion. Note that the "cradle" of western civilization, the fertile crescent, is riven by active faults, as is the Aegean Sea and coastal China, all primary centers of early civilization. Could an occasional tremblor serve to 'shake up' people in a positive way?
"The Los Angeles area remains the second-largest metro area in the US and, in addition to the film and television industries, technology giants including SpaceX, IBM, and Google maintain offices around LA employing thousands of workers. ®"
Offices! Well, that's a relief. It's not as if it was going to hit anywhere important!
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