Where Do The Earthquake Faults Lie In The San Francisco Bay Area

good evening I'm science editor Brian Hackney and love quakes or Hatem the Bay Area is the most lived upon fault system in the world no matter where you're watching this from you're within a few miles in some cases within a few feet of a potential major earthquake epicenter as you'll see in the next 60 minutes as Kron 4 news shows you where the fault lies the faults in the Bay Area very complicated system if we were say down in Southern California all of the plate movement is fundamentally on one structure it's only one single source quakes as you come up into the Bay Area the slip on the San Andreas begins to display off it's like you're coming up the trunk of a tree and suddenly you hit the branches and then you go out to smaller branches and then you've got little leaves at the end the san andreas system is the same way we come up towards the Bay Area and first the Calaveras fall splits off and then San Andreas keeps going but the Calaveras sense diverges becomes the Hayward that he would become Suraj is creepy the Rogers Creek becomes a la cama and then part of the Calaveras also becomes the Greenville phone which becomes the Concord Fault which becomes the Green Valley fault so each one of these faults now becomes a source of an earthquake so we go from south of the Bay Area where we fundamentally have the San Andreas that's one big source up into the Bay Area where we have now many sources and so we're sitting here in the Bay Area we really are a plate boundary the movement between North America the North American plate and the Pacific plate is accommodated on this set of faults that marches across the Bay Area but of the dozens of faults that have been identified in the Bay Area there is one that has always stood out as being the most dangerous and it's not the San Andreas the fault that scares me the most in the Bay Area is the Hayward Fault the Hayward Fault definitely makes me the most nervous it's under freeways it's under water lines if you on top with a fault and the fault moves good luck I don't want to be there so we take to the air from Fremont to San Pablo to show you where the Hayward Fault lies geologist Keith Kelson of William lettuce and associates is our guide from the air USGS geologist Jim lien camper from the ground this is where creep is first recognized on the boat we're in South Fremont with a creepin section of the Hayward Fault emerges paralleling 680 slicing through Mission Boulevard from this point on the fault is almost constantly in motion on the surface sing-along heading north first through open space and in half a mile the fault comes within only a few feet of dozens of homes here at least the fault misses them but in this nearby neighborhood it disappears underneath homes a real problem because of that constant creep on the fault you can even spot the evidence from the helicopter see that crack in the street this is the Hayward Fault this crack in the street yes okay and so relative to each other how fast are you moving I bet a third of an inch a year that way but if you look at the line of the fault they go straight into those houses right yes the fault is almost in Phil Howard's front yard Phil and I have met before you first moved here in 63 yes this has caused any big problems broken water mains yeah not yet heading north through Fremont the fault skirts the western edge of Lake Elizabeth on the ground look how much it's displaced curbs on one side of rocket drive on the other side then head straight into this apartment the residents here know that this is like close to the Hayward Fault but the resident doesn't speak English oh no blast when English habla espanol and I don't speak his language Oh Farsi oh he speaks Farsi I don't speak Farsi still pushing north just across from that pond the Fremont BART stations parking lot is built on top of the main trace of the Hayward Fault speeding north from Fremont now the fault hugs the foothills until it takes legendary aim at its namesake lovely beautiful downtown here don't forget the day a large quake hits six feet of offset is expected near the epicenter the fact that the fault creeps gives us an idea where the rupture will be at the Hayward plunge that creep has cracked the sandbox wall and that sandbox closed to be straight The Fault crosses it and it's pushed it north about a foot just beyond look at the split in that otherwise perfect stone wall so imagine what that six feet of offset will do to the scores of buildings it intersects it goes right through downtown Old City Hall in Hayward has a trace that clips the building so now it's just used for storage but above and beyond old city hall there are plenty of buildings that are inhabited day in and day out and when the quake hits they will almost certainly be split so we're standing on the Hayward Fault right now and the hair would fall goes right into that building that's right it's stunning to see we look down the top of the building the fault slices underneath and you can see the slant in the wall because half of the building is being pushed north by creep on the fault how many buildings are there like this I mean are there are there thousands are there hundreds are there dozens well i at least scores of them I would say hundreds I don't know if possibly I'm Brian Hackney from channel 4 you know the Hayward Fault runs right through the building yeah you do but not many know that it's possible that we're overdue for the next big quake here the evidence is in that pond which corresponds to the 1868 earthquake with this layer Jim lien campers dug into the history of the Hayward Fault buried there and found evidence of for large Hayward quakes in the past 500 years so what does that work out to one every it averages a hundred thirty years between earthquakes the last one was in 1868 so you could say the next one was due in 1998 scary except that the hundred and thirty year average is plus or minus forty years so there's decades of swamp in the average one thing we do know there is enough energy stored that it is possible to have an earth right now of magnitude six six never larger there was tremendous damage to freeways in Kobe Japan after their quake imagine the damage the rupture will do to our freeways the fault slices 580 at San Lorenzo and then up the road cuts it again at the intersection of 580 and highway 13 in Oakland and from there Caltrans couldn't resist the canyon carved through they by the Hayward Fault it made a pretty good road bed for highway 13 which follows the fault which veers off occasionally like it does in Montclair where it plunges directly into buildings so to follow the fault from Montclair just follow highway 13 where it slices its intersection with highway 24 now you can see why experts estimate that there will be 1700 road closures after a big quake on the Hayward Fault and roads won't be the only problem just north of 24 the fault slices the massive Claremont water tunnel and it severs the BART tunnel in the Berkeley Hills the Train only has 2 feet of clearance on either side a rupture could easily offset the tracks 6 feet you've read our plans very well that is true of a seismic event that could cause actual ground rupture is extremely difficult to guard against now north from the tunnel to where the fault cliff grounds of the Claremont Hotel up to the Cal campus and the unkindest cut of all the Hayward Fault practically divides Memorial Stadium into you can look up the stadium wall and see one side pushing north 13 inches since 1924 at that rate the west side of the stadium pushed into San Pablo Bay in four million years Yvonne Fox is one of thousands who live within a few feet of the fault in Berkeley it crosses Spruce Street those seams in the asphalt were poured back in 1930 they lined up when they were new of course but slip on the Hayward has staggered them so that now 70 years later they look this today someday there will be six times as much displacement in 20 seconds then north from Kensington the fault intersects so many houses that which are about to see is inevitable down below follow the curb offset to where the fault splits a foundation so that the bedrooms are on the Pacific plate the living rooms are on the North American and off it goes until finally the Hayward Fault disappears off point panel somewhere under the waters of San Pablo Bay Brian as you say how worried can we be like Darlene says the house has been riding well from Phil Howard's intersection in South free month to Yvonne's in North Berkeley it's 35 miles that's about the length of the rupture expected in a magnitude 7 you know what I believe in crashing and burning in the place you love that's my philosophy

Channel: longbeach225

Views: 49,085

Rating: 4.8791208 out of 5

Keywords: San Francisco Bay Area, Loma Prieta Earthquake, 1906 Earthquake, Earthquake preparedness, The Next Big One, Hayward Fault, San Andreas Fault, Japan Earthquakes, Tsunami

Id: VUvrA_dBSow

Length: 10min 48sec (648 seconds)

Published: Sun Oct 18 2009

Reddit Comments

[u/[deleted]]

hahahah! "Habla Espanol?" "Oh, Farsi..."

[u/clunkclunk]

I live about a mile away from that. Thanks for the heads up.

[u/merreborn]

Bought a place 1/3 mile from the Hayward fault.

At least it was dirt cheap.

Google earth data from USGS: http://earthquake.usgs.gov/regional/nca/haywardfault/

lol. I've parked right on top of the fault to eat at a restaurant 20 feet from it.

[u/im-not-rick-moranis]

so not because it's more likely to quake, but because of the infrastructure and building on the fault?

[u/JoeBMX]

6:08 they're standing in my work parking lot... great... Glad I get the pleasure of sitting here for 40 hours a week.

[u/reiduh]

Hayward City Hall lies dormant since 1989 – a whopping decade or so of usage – after construction atop its namesake fault…