Site Map/Alternate Navigation Skip to Main Content

125 Years of Sound Science, serving society

In the News

KQED Radio Forum: New Forecast Increases Odds for Huge Earthquake in California

March 12, 2015

Guests: Morgan Page (USGS Pasadena), Patrick Otellini (City and County of San Francisco), Richard Allen (BSL), Tim Dawson (California Geological Survey)

View on KQED Radio website

NBC logo

Obama Urges Early Earthquake Warning System

February 4, 2015
Jean Elle

California lawmakers say President Barack Obama's recommendation to spend $5 million next year on an early earthquake warning system for the West Coast represents a significant breakthrough. logo

UC Berkeley marks 100th anniversary of campus landmark

February 3rd, 2015
Amber Lee

BERKELEY, Calif. (KTVU) -- On the UC Berkeley campus Tuesday night, officials launched a year-long celebration marking the 100th anniversary of the prominent clock tower known as the Campanile with a special show.


Live music was provided by a carillon, a piano-like instrument played by musicians up inside the clock tower blended with simulated sounds of bells.

The composition they played was named "Natural Frequencies," music driven by a seismometer buried 70 feet below ground on campus that measures the earth's movements.

Full story at

LA Times logo

California receives U.S. funding for earthquake early-warning system

December 14, 2014
Rong-Gong Lin III, LA Times

Napa quake house damage

A home in Napa, damaged by a 6.0-magnitude earthquake in August. (Alvin Jornada / European Pressphoto Agency)

California has received congressional funding to begin rolling out an earthquake early-warning system next year, capping nearly a decade of planning, setbacks and technological breakthroughs, officials said Sunday.

Scientists have long planned to make such a system available to some schools, fire stations, and more private businesses in 2015, but their effort hinged on Congress providing $5 million. The system would give as much as a minute's warning before shaking is felt in metropolitan areas, a margin that experts say would increase survival.


The early-warning system is considered a major advance in seismic safety because it can give the public crucial seconds to prepare for the effects of shaking. Scientists eventually want to make alerts available to a wider public via phones, computers and special devices, such as modified weather radios, once the network is refined.

Full story from LA Times

CBS Money Watch logo

California professor builds his own home earthquake detector

September 12, 2014
Bruce Kennedy, CBS MoneyWatch

Josh Blum hands and homemade detector

Berkeley astronomer Joshua Bloom says his home-made detector cost him about $100 -- and is built from a $35 minicomputer, a speaker, a Wi-Fi adapter and an SD memory card. It also uses Shake Alert, a software developed by researchers at Berkeley's seismology lab, and is linked to earthquake sensors all over California.

"Those sensors wind up shaking and send their signals to a central computer," Bloom told CBS station KPIX 5 -- signals that also broadcast an alert on his home device.

And it apparently works. Bloom says the detector woke him up about five seconds ahead of last month's Napa quake with an automated voice message, saying "Earthquake! Light shaking expected in seconds."

Video and full story at CBS Money Watch

Private Sector Takes Role in Advancing Quake Early Warning

Full story from NBC Los Angeles

Public Officials Support Berkeley's Earthquake Warning System

Full story at UC Berkeley News Center

Mother Jones logo

Earthquake warning systems exist. But California won't pay for one.

August 26, 2014
Alex Park, Mother Jones

Bricks fallen on car

As Bay Area residents clean their streets and homes after the biggest earthquake to hit California in 25 years rocked Napa Valley this weekend, scientists are pushing lawmakers to fund a statewide system that could warn citizens about earthquakes seconds before they hit.

California already has a system, called ShakeAlert, that uses a network of sensors around the state to detect earthquakes just before they happen. The system - a collaboration between the University of California-Berkeley, Caltech, the US Geological Survey (USGS), and various state offices - detects a nondestructive current called a P-wave that emanates from a quake's epicenter just before the destructive S-wave shakes the earth. ShakeAlert has successfully predicted several earthquakes, including this weekend's Napa quake. It could be turned into a statewide warning system. But so far, the money's not there.

Full story at Mother Jones

Peggy Hellweg and news anchor CBC logo

Berkeley's Earthquake Early Warning System

August 25, 2014
CBC News

Full story and Video at CBC News (Canada)

Looking for the Holy Grail in earthquake prediction

ABC 7 KGO logo

March 24, 2014
Wayne Freedman

"It is one of the stranger juxtapositions in science. Cass Winery in Paso Robles, where they pull more than wine from the soil. Look up there, high on the hill. It's a deeper quest. "At other sites we hit granite, we hit limestone." You will find many materials in California's unpredicatbel San Andreas earthquake fault which has a history of striking without warning. But maybe not in the future if Dr. Peggy Hellweg finds what she is looking for. A relatively new discovery: tremor waves..."

Photo of Lawson Adit entrance
San Francisco Chronicle logo

UC Berkeley taps its old mine shaft to study Hayward Fault

March 16, 2014
Will Kane

Mining 101 on the UC Berkeley campus a hundred years ago: the basics of dynamite, shoring a mine shaft, mine surveying and mine rescue.

And it wasn't just mining theory. The students, 18, 19 and 20 years old, actually blasted and dug a shaft, called the Lawson Adit, into the rocky hills on the northeastern corner of campus.

The shaft, which before a series of cave-ins ran nearly 900 feet into the earth just east of the Hearst Mining Building, still stretches some 200 dark, damp feet into the earth, but now sits mostly neglected behind an unassuming locked gate.

Earthquake researchers hope to install seismographs and high-frequency microphones that can detect the squeals of the nearby Hayward Fault later this year, but for now the adit is a mostly unknown bit of Berkeley - and Bay Area -history.

Read more at SF Gate...

Watch the story from KPIX...

Scientific American logo
Photo of destruction from Loma Prieta quake

Who Will Pay for an Earthquake Warning System on the West Coast?

Temblor early warning systems are real—and making their U.S. debut

Feb 6, 2014
By Amy Nordrum

A few weeks ago seismologist Tom Heaton was on the phone with a reporter extolling the virtues of a new earthquake early warning system he helped invent. Suddenly, an alert flashed across the computer screen in his Los Angeles–area office. “Oh, it just popped up! There was an earthquake in San Francisco and the waves will get to me in about two and a half minutes,” Heaton said with a glance. “But it's a [magnitude] 2.8 so we won’t feel it.”

Heaton, director of the Earthquake Engineering Research Laboratory at the California Institute of Technology, is part of the team of California researchers behind the new warning system, called ShakeAlert. It is triggered by the earliest waves of a quake, which are too subtle for humans to feel.

Read more at Scientific American...

"If there's a prominent commonality in these signals, it might tell us something about the natural response of the stadium, or the stadium-soil system"
  - Doug Dreger, UC Berkeley seismologist and 49ers fan

Seattle NFL stadium now wired for crowd-quakes

17 January 2014
Alyssa Botelho

Come Sunday in Seattle, the CenturyLink Field American football stadium will be rocking – and there'll be seismic sensors there to prove it.

The stadium is home to the National Football League's Seattle Seahawks and renowned for its raucous crowds. In January 2011, the team's Marshawn Lynch ran his way into team history with an improbable game-winning touchdown (pictured), the reaction to which registered at a seismic station 90 metres from the stadium.

Now the stadium itself is wired to pick up crowd tremors, and starting last week, researchers at the Pacific Northwest Seismic Network (PNSN) began streaming live seismic readings out to fans, and using the experience to test their readiness in case a real earthquake strikes the seismically active region.

Read more at New Scientist...

NPR logo
Photo of destruction from Loma Prieta quake

West Coast's Early Warning System For Quakes Still Spotty

December 26, 2013
Richard Harris, NPR

Earthquake scientists on the West Coast would like to build a system that would give people a bit of warning before they get jolted with strong shaking from a distant quake.

Seismic waves take time to travel from the epicenter, which means such a warning system could issue alerts ranging from a few seconds to a few minutes. A prototype has been developed for the region, seismologists say, but the complete network still lacks funding, and has big gaps outside cities.

Read more at NPR...

"We can now do a better job of swiftly estimating the magnitude of large earthquakes as they rupture the ground, and we have shown that we can successfully process the data in real time."

San Francisco Chronicle logo

GPS stations key to state's quake warning system

Decenber 12, 2013
David Perlman, San Francisco Chronicle

Earthquake scientists have found powerful new tools to alert Californians when distant earthquakes are about to cause dangerous ground-shaking where they are. Global Positioning Systems, high-tech versions of the devices that guide ships at sea and drivers through unfamiliar city streets, can instantly measure even tiny disruptions of the Earth's crust caused by major quakes, said Richard Allen, director of the UC Seismological Laboratory at Berkeley.

"We can now do a better job of swiftly estimating the magnitude of large earthquakes as they rupture the ground, and we have shown that we can successfully process the data in real time," he said, reporting the advance Thursday at a meeting of the American Geophysical Union in San Francisco.


screenshot of Peggy

KIRO 7 investigates new earthquake alert system

November 8, 2013
Graham Johnson, KIRO 7

In cities around San Francisco Bay, commuter trains travel as fast as 70 miles per hour. If an earthquake strikes, passengers could fall onto one another in crowded cars and trains could derail, trapping them in tunnels.

Now, there's a new system in place to automatically slow the trains to a safer 26 miles per hour before the ground begins shaking.

It's the first phase of an earthquake early warning system for the U.S. West Coast, and scientists have hopes of expanding it widely to include warnings to the public.

Watch the video at

Bay Nature logo

Peggy Hellweg monitors world's earthquakes

November 1, 2013
Sam Whiting, San Francisco Chronicle Magazine

In a conference room on the second floor of McCone Hall at UC Berkeley sits an old-style seismograph with a mechanical pencil, ticking away as it marks tremors on a roll of white paper. Across the hall sits Peggy Hellweg, operations manager of the Berkeley Seismological Laboratory.

On duty: We collect and provide data, report on earthquakes in Northern California, and train new seismologists and do research with the data that we collect. Our funding comes jointly from the federal government and the state, with some from the university.

On education: I grew up in Lafayette. I studied physics at UC San Diego. I needed a part-time job and got a job with a group of seismologists who needed a programmer. I was learning the science behind the programs I was writing, and that was seismology.

Read more at sfgate

KTVU logo KTVU logo

State’s earthquake warning system promised but not funded yet

October 17, 2013
Ken Pritchett, KTVU

BERKELEY, Calif. — Thursday marks 24 years since the Loma Prieta earthquake struck the Bay Area, killing 63 people, and what sets this anniversary apart from previous ones was that California was planning to build an earthquake early warning system.

Governor Brown signed a bill to create a statewide network of seismic sensors last month. But, no money was allocated and funding must be found.

Read more and watch the video at KTVU

Bay Nature logo

Is There Earthquake Weather? And Was That It?

October 16, 2013
Sean Greene, Bay Nature

I made a $100 bet on Monday that there wouldn’t be an earthquake.

I was eating lunch in the courtyard at the Berkeley Graduate School of Journalism, where I am a student, and a classmate claimed, “This is earthquake weather!”

Read more at Bay Nature

"I applaud Governor Brown for his vision and leadership. We live in earthquake country. He understands that when it comes to earthquakes in California, it is not a matter of if, but when," said Senator Alex Padilla.

Calif. Gov. Brown Signs Sen. Padilla Bill to Create California Earthquake Early Warning System

September 24, 2013
Christopher Simmons, California Newswire

Governor Jerry Brown today signed Senate Bill 135 by Senator Alex Padilla (D-Pacoima), which requires that the Office of Emergency Services develop a comprehensive statewide earthquake early warning system to alert Californians in advance of dangerous shaking.

“When the system is up and running, Californians will be provided critical seconds to take cover, assist loved ones, or pull over safely to the side of the road. It will allow time to stop a train and power down critical infrastructure. Most importantly, it will save lives,” said Senator Alex Padilla.

“California’s best science and technology will be used to detect seismic activity and alert people in advance of destructive shaking. An early warning system will also help public safety personnel identify and respond more quickly to areas hardest hit by a quake,” Padilla added.

“We need to develop this system without delay. California is going to have an earthquake early warning system, the question is whether we have one before or after the next big quake,” Senator Padilla said. More...

“The good news is that the technology now exists that can give us a little heads-up that allows us to take cover, help loved ones, power down industrial equipment, slow down trains or bring them to a stop and minimize the damage.”

San Francisco Chronicle logo

Bill for quake-warning system goes to governor

September 13, 2013
David Perlman, San Francisco Chronicle

Development and operation of an early-warning system that would swiftly alert Californians when a damaging earthquake ruptures the ground anywhere in the state received unanimous approval by the state Legislature on Thursday.

The bill by Sen. Alex Padilla, D-Pacoima (Los Angeles County), is expected to be signed by Gov. Jerry Brown, legislative aides said.

Early versions of an earthquake early-warning system similar to one that is already operating in Japan have been under development and testing by scientists at UC Berkeley and the U.S. Geological Survey in Los Angeles for the past 15 years.

Padilla estimated a full-scale system would cost about $80 million to build and his bill, SB135, directs the Office of Emergency Services to find the money.

Elements of a partial working system under development since 2002 have been financed by private and public grants of more than $15 million, said Richard Allen, director of UC Berkeley's Seismological Laboratory.


UC Berkeley News Center logo

New model of Earth’s interior reveals clues to hotspot volcanoes

September 5, 2013
Sarah Yang, UC Berkeley Media Relations

Scientists at UC Berkeley have detected previously unknown channels of slow-moving seismic waves in Earth’s upper mantle, a discovery that helps explain “hotspot volcanoes” that give birth to island chains such as Hawaii and Tahiti.

Unlike volcanoes that emerge from collision zones between tectonic plates, hotspot volcanoes form in the middle of the plates. The prevalent theory for how a mid-plate volcano forms is that a single upwelling of hot, buoyant rock rises vertically as a plume from deep within Earth’s mantle – the layer found between the planet’s crust and core – and supplies the heat to feed volcanic eruptions.

However, some hotspot volcano chains are not easily explained by this simple model, suggesting that a more complex interaction between plumes and the upper mantle is at play, said the study authors.


3D View of the mantle beneath the Pacific Ocean “… We now have a clearer picture that can help us understand the ‘plumbing’ of Earth’s mantle responsible for hotspot volcano islands like Tahiti, Reunion and Samoa.”

"The app is mainly designed for people who do not yet understand earthquakes, which is something that people who do understand earthquakes worry about"
Daily Cal logo

New MyQuake app educates on earthquakes

August 16, 2013
Nico Correia, Daily Cal

MyQuake, a new free iPhone app released by the Berkeley Seismological Lab, intends to shake up the way people think about earthquakes.

The app, developed by the lab and students Rohan Agarwal and Cora Bernard, aims to teach iPhone users about earthquakes and encourage safety.

Maps show recent earthquakes throughout the world as well as historically destructive earthquakes in California to keep users thinking about earthquakes — even when the effects are not catastrophic.

“The app is mainly designed for people who do not yet understand earthquakes, which is something that people who do understand earthquakes worry about,” said Peggy Hellweg, the lab’s operations manager, in an email. “(We) try to help people understand about earthquakes, what their effects can be and how people can prepare themselves. This app helps.” More...

East Bay Express logo

Sounding the Alarm:

An early warning system would save thousands of lives when the next major earthquake hits. But will California find the money to implement it?

May 1, 2013
Azeen Ghorayshi, East Bay Express

At 2:46 p.m. on March 11, 2011, the Pacific Plate, just off Japan's northeast coast, suddenly thrust downward, unleashing a monstrous, 9.0-magnitude earthquake that rocked the country for the next six minutes. The massive Tohoku quake and resulting tsunami are believed to have killed at least 16,000 people and injured 6,000 more. Another 2,600 people are still missing and presumed dead. The quake was the most powerful to ever strike Japan, and was the fourth-largest ever recorded. It also was the first earthquake to be heard in outer space, and was the most expensive natural disaster in human history, generating $235 billion in total damage. But there was a silver lining, if you could call it that: Tohoku was also the first time that Japanese citizens were given the precious, if limited, gift of time.


Richard Allen "Seismologists don't like to make very many predictions," Allen said. "But I will make you one prediction, and that is that we will definitely build an early warning system in California. The only real question is whether it's immediately after the next big earthquake, or whether we actually manage to build it before."

San Francisco Chronicle logo

Earthquake Early Warning System Passes Major Test With Quake

Earthquake Early Warning cartoon

March 13, 2013
Doug Stevens, Los Angeles Times

In the seismic annals of California, Monday’s 4.7 earthquake was little more than a footnote. It gave Southern California a small morning jolt but caused no damage and was largely shrugged off by noon. But in one important way, the quake was highly significant because it marked an advance in California’s burgeoning earthquake early warning system.

The quake struck in the desert town of Anza, and hundreds of sensors embedded in the ground immediately sent an alert to seismologists at Caltech in Pasadena. They had 30 seconds warning before the quake was felt there. “It was right,” said Kate Hutton, a seismologist with Caltech. “I sat really still to see if I could feel it and it worked.” More...


San Francisco Chronicle logo

Earthquake Warning System Makes Every Second Count

Earthquake Early Warning display screen

February 6, 2013
Luke Abaffy, Engineering News-Record

An early warning system that predicts an earthquake's approaching shock wave up to a minute before it strikes is ready to become operational throughout California. Further, a recently proposed bill would fund expansion of the system.

The bill, introduced by state Sen. Alex Padilla (D), would support the ShakeAlert system, developed by the U.S. Geological Survey and an international coalition of universities. It is based on Japan's primary-wave, or p-wave, detection system. More...


Warning: It's a quake

Lawmakers should put today's technology to use and pursue a statewide early alert system.

February 3, 2013
LA Times Editorial

The San Andreas Fault is overdue for a powerful earthquake, geologists say, but there is no way to predict when it will strike. Yet as Japan has demonstrated, it is possible to detect the start of a quake and alert at least some potential victims moments before the most damaging shocks hit. That country's detection and warning system helped minimize the casualties from the massive quake off its coast in 2011, although the resulting tsunami claimed thousands of lives.

Last week, scientists at the U.S. Geological Survey, the California Institute of Technology and UC Berkeley, backed by state Sen. Alex Padilla (D-Pacoima), called on the state to develop a similar system. They want to upgrade the existing California Integrated Seismic Network, a joint effort by federal, state and university geologists to monitor seismic activity along multiple fault lines, to deliver alerts to the public when a sizable quake strikes. It's an idea worth pursuing, although policymakers shouldn't minimize the challenges that remain. (Read more...)

California weighs $80 million early warning system...

Earthquake Early warning news conferencePhoto:The Associated Press

January 31, 2013
David Knowles, New York Daily News

When it comes to major earthquakes, the difference between life and death can sometimes be measured in seconds. A bill introduced in the California Senate calls on the state to build the nation’s first earthquake early warning system to give residents as much as 60 seconds to prepare themselves for the worst.

“A fully developed earthquake early warning system would provide Californians critical seconds to take cover, assist loved ones, pull to the side of the road, or exit a building. It could allow time to stop a train or power down other critical infrastructure,” Sen. Alex Padilla, the bill’s sponsor, said in a news release. “The earthquake warning would not only alert the public, it would also speed the response of police and fire personnel by quickly identifying areas hardest hit by the quake.”


Logo for Quest

What Makes California's Quake Warning System So Timely?

collapsed Cypress Viaduct in Oakland

Andrew Alden
QUEST Northern California Blog

Earlier this week, State Senator Alex Padilla went before the cameras with a group of earthquake scientists to kick-start California into building the world's best earthquake early-warning system. Does such a thing really work? And why should we start now?

Early-warning systems are not a scientific boondoggle; they really work. First things first, though: these do not predict earthquakes. Instead, they're automatic systems that detect quakes right at the epicenter, and measure their size almost instantly.


San Francisco Chronicle logo

Earthquake alert system may be coming

Earthquake Early warning news conferencePhoto:Reed Saxon, SF Chronicle

January 28, 2013
David Perlman, San Fransisco Chronicle

An early warning system that flashes imminent danger that a damaging earthquake is about to strike is ready to operate in California, seismic experts said Monday as a legislator introduced a Senate bill to develop the first $80 million system across the state.

After 10 years of research and testing, the system called ShakeAlert could warn emergency workers and the public as much as a full minute before a big quake ruptures the ground along any of the faults in the state, the experts said. More...


GeoSpace logo

California's faults have synchronized bursts of movement

December 12, 2012
Geospace blog

Twenty years after the Loma Prieta earthquake, seismologists are still learning from the faults that zigzag across California. Now, new information on the movements of two of these faults suggests they are shaking in tandem.

Some of the worst earthquakes in California have occurred along the San Andreas Fault, including the disastrous 1906 San Francisco earthquake. In 1989, the magnitude 6.9 Loma Prieta earthquake shook Northern California, with an epicenter about 70 miles south of San Francisco.

Different sections of the 810-mile San Andreas Fault move at different rates. Some stretches, like the 150 miles between Loma Prieta and Parkfield, typically creep along. The two sides move steadily past each other, the friction creating mini-quakes that are barely felt.

Read more....

Logo for BBC

Phones to be pocket seismometers

December 5, 2012
Paul Hagey, BBC

The smartphones in our pockets are about to get even smarter.

Scientists want these ubiquitous gadgets to be put to work helping them detect and investigate earthquakes.

The devices contain accelerometers and a team at the Berkeley Seismic Laboratory says the mechanisms are capable of monitoring tremors.

Watch Video

BART puts early earthquake warning system to use

Septempber 25, 2012
KRCR News Channel 7

BERKELEY, Calif. (KGO)--UC Berkeley seismologists will be testifying in Congress later this week, urging the government to build and pay for an early earthquake warning system which they've developed. BART, which is now using the system, just launched it a couple of months ago. It has become the first train system in the country to incorporate the early earthquake warning system.

The siren gives a minute's warning before a quake hits, enough time to protect yourself. Sound futuristic? Well, it's not. That technology is already here. Seismic scientists from UC Berkeley have successfully tested it. They've planted sensors all over the Bay Area which can detect seismic waves from an earthquake's epicenter.

Electronic alerts are sent over the internet to end users like BART. The train system has developed a software program that analyses that data, then automates a response. "We then use that software to initiate a command through our central computer that sends a command to the field that puts the trains into breaking mode and limits them to 25 miles per hour at top speed," BART Chief Engineer Carlton Allen said


Warning where the Big One will hit

The control room at the Japanese Meterological Agencywith its earthquake early warning system.

December 8, 2011
University of California Research
by Wallace Ravven

UC Berkeley is partnering with two other universities, a philanthropic foundation and industry to conduct earthquake research that could lead to a warning system. People could then have time to dive for cover, and transportation and utility systems could shut down operations.

A major fault ruptures somewhere along the 70-mile-long Hayward Fault. But where? Is the break at just one point along the restless slab, or many?

Answers are crucial to predicting where the worst shock will hit and how much damage it will cause. The underground details can provide a precious five- to 30-second warning between the time a temblor is detected and when its destructive energy reaches the surface.


Quake warning system for West Coast nears reality

November 30, 2011
Contra Costa Times
by Suzanne Bohan

The devastating 1868 Hayward fault earthquake shook loose the first plausible idea for warning people of imminent ground shaking.

A Bay Area physician proposed using telegraph cables into San Francisco to transmit energy from an earthquake to ring a warning bell.

A high-tech version of that idea is finally close to reality along the West Coast.

This summer, UC Berkeley, the U.S. Geological Survey and two other universities began testing a prototype earthquake warning system. It would alert people, hospitals, transit systems and factories seconds to a minute before a major quake.


Gordon and Betty Moore Foundation awards $6 million for earthquake early warning research

November 29, 2011
UC Berkeley Media Relations
by Robert Sanders

The Gordon and Betty Moore Foundation has awarded $6 million to three West Coast universities to create a prototype earthquake early warning system for the Pacific Coast of the United States.

The grant will allow seismologists at the University of California, Berkeley; California Institute of Technology (Caltech); and University of Washington, Seattle, in collaboration with the U.S. Geological Survey (USGS), to learn about the science of earthquakes and the best way to capture and analyze seismic data. The goal is to give schools, utilities, industries and the general public as much time as possible - most likely seconds to several minutes - before the ground begins to shake.


Seismic Concerns In San Francisco

October 29, 2011
KRCR News Channel 7

Logo for Bay Nature Magazine

Got Quakes on the Mind?: Big One's Still Coming, Says Seismologist

October 28, 2011
Bay Nature Magazine
by Paul Hagey

You probably felt only three or four of them, but there have actually been 16 brief rumbles along the Hayward Fault in the last week in Berkeley. As little quakes tend to do in Earthquake Country, these have shaken the idea of the Big One loose from its usual obscurity and brought it to the front of everyone's minds.

And for good reason. The US Geological Survey estimates that of the seven faults most likely to generate a magnitude 6.7 or larger earthquake in the Bay Area, there's a 63 percent chance that at least one of them will break in the next 26 years. There's a 31 percent chance that it will happen along the Hayward Fault, the greatest chance of the seven. The fault runs for 74 miles along the western base of the East Bay Hills from San Jose to San Pablo Bay.