Cracking the Earthquake Code Do earthquakes provide magnetic warning signs?
Roberta Kwok puts her ear to the ground.
Illustrated by Sarah Adler and Lauren
Benson. 
Illustration:
Sarah Adler Tom Bleier is praying for an
earthquake. An engineer who designed and built his own house,
Bleier lives on a densely wooded ridge in Portola Valley, California,
less than half a kilometer from the San Andreas fault. In a nearby
field, hes planted an instrument to track magnetic signals from the
Earth. Its a gangly contraption resembling a hotel mini-fridge on
stilts. Weve been desperate for another
earthquake, he says. Bleier doesnt have a
death wish. His company, QuakeFinder, monitors a far-flung network of these
sensors along Californias fault lines, from Eureka to the Mojave
Desert. Theyre banking on an old and controversial theory that
blips in a regions magnetic field could herald the rumblings of the
most destructive earthquakes. With enough luck, Bleier believes,
QuakeFinder will predict them. The mere
mention of earthquake forecastinga field populated by reports of
mysterious lights, unexplained temperature shifts, and highly attuned
catsis enough to make some geophysicists roll their eyes. But
magnetic alarms arent just quackery, insists a small cohort of
researchers. Bleier claims one of his sensors picked up magnetic
pulses before a magnitude 5.4 quake that shook the Bay Area in
October 2007. A NASA physicist has found that rocks generate
electricity under stress, offering a possible explanation for
magnetic jitters at the surface. And Stanford University engineer
Antony Fraser-Smith, whose
observation of a signal before the 1989 Loma Prieta quake remains the
strongest evidence to date, is so frustrated by the scientific
communitys lukewarm response that hes lobbying members of Congress
to set up magnetic sensors at earthquake hotspots around the
world. We have 34 million people in California
all sitting around and paying taxes and expecting the federal
government to do something about earthquakes, and yet no one is
trying to verify those measurements, Fraser-Smith says. It really
irritates me. Magnetic signals could do for
earthquakes what weather satellites did for hurricanes, giving
people enough time to locate their families, move to safer areas,
and turn off fire-igniting gas lines, Bleier says. But critics of
earthquake prediction, burned by exaggerated claims before, remain
deeply skeptical. A regions magnetic field is a morass of meaningless
noise, they say, warped by everything from solar activity to electric
trains to cell phones. From their perspective, deciphering a real
earthquake signal amidst the junk is akin to picking out the hum
of a single car zipping past on a crowded freeway. And researchers
have failed to link these signals consistently to all earthquakes,
making the claim of predictive ability at best, a vast overstatement,
says Richard Allen, a seismologist
at UC Berkeley. So far, the nations primary
earthquake-monitoring agency, the U.S. Geological Survey (USGS),
has declined to fund Bleiers work. Were hanging on by a thread,
he says. QuakeFinder subsists on money from its parent company,
the aerospace engineering firm Stellar Solutions, and a small
NASA grant. But unless it detects a signal from the next big quake,
the companys network of sensorsthe largest in the world, its website
claimswill probably disappear. Messages
from the underground Earthquake
prediction has fallen on its face before. In the 1970s, scientists
declared they could detect upcoming earthquakes by monitoring bulges
in the ground, a strategy that failed upon further testing. A Greek
group created a furor in the 1980s with claims that electricity
sensors could successfully predict earthquakes, but critics called
their data contaminated and their predictions too vague. Meanwhile,
reports of magnetic signals trickled in, including spikes recorded
before earthquakes in Alaska, Armenia, and Guam. The most startling example arrived in 1989, when
the magnitude 6.9 Loma Prieta earthquake struck the San Francisco
Bay Area. At the time, Fraser-Smith was monitoring magnetic
fluctuations in the Santa Cruz Mountains for unrelated research on
Navy submarine communication. His sensor was only seven kilometers
from the epicenter. When he checked the sensors records after the
quake, he found the first magnetic wobbles a month in advance,
followed by a lower-frequency roar. In the hours before the quake,
the signals were so big that the computer spat out calibration error
messagesthe first such warning in the instruments two years of
monitoring. Fraser-Smiths report at that
falls American Geophysical Union meeting immediately attracted
attention. The USGS asked him to monitor Parkfield, a
quake-prone area in Central California, but pulled his research
funding after several years went by without a rumble. (During that
time, Fraser-Smith failed to pick up a signal from the deadly Northridge earthquake, a result he attributes to his
sensor being too far away.) Opposing teams wrangled over the meaning
of Fraser-Smiths Loma Prieta data at a 2007 geophysics meeting in
San Francisco, with USGS scientists on both sides. One group
concluded the spikes were just data corruption. It
was a real stab in the back, says Fraser-Smith.
 | Photo: Roberta
Kwok | Stanford
engineer Antony Fraser-Smith displays his magnetic recordings from
October 1989, when a large earthquake struck near Santa Cruz,
California. | | |
Now a retired professor with white
hair brushed neatly back from his forehead, Fraser-Smith still keeps
wrinkled graphs of his Loma Prieta measurements posted on his wall
at Stanford. In a clipped New Zealand accent, he dismisses the
idea that scientists cant tell new signals apart from the familiar
patterns of background noise. I am an expert,
and we have no trouble distinguishing these signals, says Fraser-Smith.
I have tremendous confidence that electric and magnetic field
measurements will tell us a whole lot. And yet theyre just not
being used. Its really, really sad. Fraser-Smith
plans to write members of Congress proposing a network of sensors
around the Pacific Rimthe so-called Ring of Fire where earthquakes frequently strike.
Three years of monitoring, he estimates, could support or undermine
a connection between magnetic signals and earthquakes. The equipment
would cost $3 million, an absolutely piddling sum compared to other
large research projects, he says. To support his argument, he
points to reports of other signals. And to a Biblical proverb:
Where there is no vision, the people perish. Bogus signals?
One of Fraser-Smiths apostles is Tom Bleier. A satellite engineer
who studied earthquake signals as a hobby for several years, he
still remembers hearing about the Loma Prieta report. I was applauding from the back of the room, says
Bleier, who is nearing retirement but speaks with the enthusiasm
of a boy showing off his first Lego creation. Bleier decided to build his own network. With
science outreach funding from his employer, Stellar Solutions, he
began constructing instruments with local high school students. In
2000, he started QuakeFinder and convinced farmers to let him set
up sensors in their fields. Now in its eighth year, QuakeFinder
has 70 sensors ranging from the Oregon border to the Southern
California desert, all transmitting data to an office in Palo
Alto.  | Photo: Roberta Kwok |
Tom Bleier, founder of
the QuakeFinder network, stands with a magnetic sensor in Portola
Valley, California, south of San Francisco. | |
| Some
transmissions, Bleier believes, contain strange signals from the
October 2007 Alum Rock earthquake near San Jose. What the heck are
those spikes? he asks, pointing to a graph resembling an EKG plot
at QuakeFinders offices. The signals started in September and
increased as the earthquake approached, bombarding the nearest
sensor with at least 1,000 pulses a day and, as in the case of Loma
Prieta, continuing for several days after the initial shock. Similar
spikes show up occasionally on other stations, but Bleier suspects
the tight Alum Rock cluster may have been a warning sign. QuakeFinders engineers are now on a CSI mission,
as Bleier calls it, to make sure the signals didnt come from somewhere
else. Theyve checked electrical equipment on the property, the
effect of passing cars, and the timing of laser blasts from a nearby
laboratory. The team still needs to analyze past transmissions to
see whether the Alum Rock pattern is truly unusual, Bleier says.
Even if it is, he isnt optimistic about how others will react.
People will throw rocks at it, he predicts. Scientists already are raising questions. Malcolm
Johnston, a member of the USGS team that critiqued Fraser-Smiths
work, says QuakeFinders results suffer from the same pitfalls as
other claims of magnetic precursors: They were recorded in an
environment clogged with noise, and because QuakeFinders sensors
are widely spaced, they only appeared on one station. Any data on a single instrument is suspect, and
anybody in the game will tell you that, he says. Earthquakes do generate magnetic signals, Johnston
says, but these generally occur during or after the quake. After
searching for 30 years without success, he believes precursory
signals are too small to be picked up. Johnston points to the
magnitude 6.0 Parkfield earthquake, which finally arrived in 2004
and was surrounded by a phalanx of high-sensitivity instruments.
The quake remained magnetically mum. These
results make it hard to justify the global network Fraser-Smith
envisions, Johnston says, though Fraser-Smith believes the Parkfield
quake was simply too small to send a signal. Johnston is dubious
about the historic signals Fraser-Smith claims as evidence; the
Alaska measurement, for instance, was taken in a motel parking lot
where engines and moving cars might have caused magnetic disruptions.
As for older reports, Johnston says the signals go to nearly zero
once scientists use modern techniques to remove sources of noise
produced by Earth's atmosphere. Almost
certainly most of this is bogus, he says. Snap, crackle, rock
NASA physicist Friedemann Freund is
used to deflecting skepticism. Described by a fellow scientist as
a thoroughly charming gentleman, Freund speaks in the same gentle
tone of voice whether hes explaining the movement of particles,
denouncing seismologists for their close-mindedness, or recalling
the time he was hit by a bullet during a rock impact experiment.
(It hurt a little bit, he says.) His research, he says, could hold
the key to explaining magnetic signals. I
came up with this relatively childish idea, says Freund in his
Mountain View office. Hes nursing a broken arm from a hiking
accident, but he holds up a small piece of black basalt with his
good hand. In the moment we start squeezing this, he says, pressing
the rock between his fingers, we start to see that this rock generates
electricity. To test his theory, Freund
salvages meter-long slabs of leftover granite from cemetery monuments
and kitchen-counter stores. He hauls them into his laboratory at
NASA's Ames Research Center, squeezing them between metal pistons
to produce electrical pulses that zing at 200 meters per second.
Fraser-Smith and other scientists question whether these experiments
will translate to the Earths crust, since water could short-circuit
the current. But Freund says its possible under the right conditions.
Imagine giant masses of rock underground, add the crushing stress
of an earthquake, and you could get big, big-time electric currents,
he says. Freund believes a little-known
chemical exchange in the rock jolts the current into action. Some
of the minerals oxygen atoms are one electron short, leaving electron
holes. Stress throws the oxygen atoms into chaos, making their
electronsand the holesjump from one atom to the next, Freund says.
He compares the situation to a movie theater with only one empty
seat: If each person shifted from one seat to the next, the empty
seat would appear to move, just as electron holes move through the
rock. The moving holes could generate strong fluctuating electric
currents in the Earth, according to Freund, and cause magnetic
changes at the surface. The theory could
also explain a slew of other pre-earthquake phenomena besides
magnetic signals, Freund says. For instance, satellites have
reported areas shining in the infrared before earthquakes. These
infrared signals could be released by oxygen atoms that pair up at
the surface of the rock, he says, adding that he has produced such
emissions in the laboratory. Other people have photographed strange
lights before earthquakes; Freund attributes these to electron holes
that create a positive charge in the air, leading to a bright corona
discharge. According to Freund, even odd animal behavior can be
explained by experiments from the 1960s showing that animals shy
away from positively charged air. The more
I dug into this, the more I realized that all the phenomena fall
into place if we understand the physics of these electron charge
carriers, Freund says. Suddenly things become very easy. Scientific sex appeal Earthquake prediction researchers do have some
allies. Alan Linde, a geophysicist at the Carnegie
Institution in Washington, D.C., believes Fraser-Smiths Loma Prieta
measurements are sound and says he was totally unpersuaded by the
data-corruption criticism. But the question of whether the quake
caused the signal is much more difficult, he says. Coming up with
more evidence wont be easy; to get instruments close enough to the
epicenter, he notes, you almost need to predict the earthquakes
location anyway. Earthquake prediction is
a hell of a sexy objective, and the temptation to get a wonderful
answer is high, Linde says. Although a few bad studies may give
the field an air of disrepute, Linde believes the research should
go on. He likens earthquake forecasting experiments to playing the
lottery: You might end up with nothing, but the payoff could be
huge. Thats how breakthroughs are made, doing experiments that
have a small chance of return, he says. But
if scientists want to use magnetic signals to predict earthquakes,
they need to observe them before all earthquakes, not just some,
says Richard Allen of UC Berkeley. So far, that hasnt happened.
They have a whole list of excuses, or reasons, as to why you dont
see them, he says. The idea that we would somehow miraculously see
these signals before future large earthquakes is not founded in any
actual information. Instead of trying to
predict earthquakes, Allen argues, we should focus on being
better-prepared for them. What people really want, he says, is for
life to go on as usual after a quakeand the best way to accomplish
that is by constructing better buildings. As an extra blanket of
protection, Allens team also is developing a warning system based
on an earthquakes first tremors (see sidebar).
A fair shake?
If QuakeFinder goes under, a more modest operation is ready to step
in. A USGS-led group of San Francisco Bay Area scientists has
scraped together NASA funding to monitor magnetic activity in the
San Francisco Bay Area. The team plans to install closely spaced
sensors in two quiet areas to increase the chance that a signal
will appear on multiple stations. The bottom
line is this sort of work has to be done much better if we are going
to convince anybody that theres any reality in these sorts of
signals, says Johnston, who will lead the study with USGS geophysicist
Jonathan Glen. Even if they pick up a signal,
it wont necessarily lead to an earthquake prediction system, Glen
says. Rocks could emit wildly different signals depending on the
areas geological features and fluid content, making confident
predictions difficult. We are really far,
far away, says Glen, who plans to exchange data with QuakeFinder.
There is definitely the potential. But to say we are anywhere near
there is disingenuous. I think its misleading. While QuakeFinders
widespread network has a better chance of catching a signal, Glen
believes his teams strategy will be more effective at determining
whether a signal is truly an earthquake precursor. Fraser-Smith is prepared to accept the possibility
that earthquakes dont transmit magnetic warnings, saying that it
would take at least 10 or 15 other examples to convince him. I
would just like to know the truth before I die, he says. It could be a while before scientists settle the
question. The Earths utterings are faint and often confusing and
few claim to know how to read them, Freund wrote in a 1999 article.
Decades of research have shown the difficulty of interpreting
potential earthquake signals. Unless scientists can learn to
translate its messages, the Earth may remain a closed book. Top
Sidebar: Take Cover!
 |
Illustration: Laura Day Benson |
If long-term earthquake forecasting
doesnt pan out, how about a few moments of warning? Scientists
at UC Berkeley have developed a system that could size up an
earthquake and sound an alarm several seconds before the ground
turns to Jell-O. Earthquake early-warning
systems already exist in countries such as Japan, Mexico, and Turkey.
Mexicos system, for instance, monitors the stirrings of an offshore
fault in the Pacific Ocean and outruns the earthquakes most destructive
waves to Mexico City. But California presents a special challenge
because its citizens live precariously close to major fault lines,
leaving little time to broadcast an impending quake. Were trying to build a system that absolutely
minimizes delays because if possible, we would like to issue warnings
to people living right in the epicenter region, says seismologist
and project director Richard Allen. To make
the speediest decision possible, Berkeleys ElarmS system squeezes information from the first
few seconds of underground pulses to calculate the magnitude and
location of the quake. If the waves are small and close together,
the threat level goes down; if theyre large and far apart, a giant
temblor is likely on the way. ElarmS then draws on data from past
earthquakes to predict the intensity and distribution of ground
shaking, creating a nearly instant map that could lead to automated
warnings. The team put its system through
a hands-off test run in 2006 to see how it performed without human
guidance. Over the course of eight months, ElarmS crunched the
numbers on 75 small earthquakes in northern California. Simulated
warning times to major cities clocked in around 40 to 60 seconds.
In October 2007, the system accurately predicted the magnitude and
ground shaking of the magnitude 5.4 Alum Rock earthquake before
anyone felt the shaking in San Francisco, Allen says. ElarmS isnt yet a full-blown warning system. The
other half of the problem is how we get that information out to
people and how people should use that information, Allen says. He
speculates that alarms could be issued through the Internet, cellphone
towers, or radio. Transportation systems and dangerous industries
could shut down automatically, and people could move to safety.
But first, his team must make sure ElarmS is accurate and rock-solid.
Top
Biographies
 Roberta Kwok
B.Sc. (biology)
Stanford University
M.F.A. (creative writing) Indiana
University at Bloomington
Internship: Idaho National Laboratory
news office
It started with sunflower
puberty. I was an English student moored in the Midwest, writing
short stories and celebrating my recent escape from the cubicles
of Silicon Valley. Chekhov had replaced Mendel; my training in
biology and computer science had begun to seep away. Then one cold March day, I spent 24 hours tailing
a young evolutionary biologist who wanted to find out how sunflowers
decide to flower, or enter puberty. I followed him into greenhouses,
recorded his words (including the expletives), wrote his storyand
realized that language could bring the humanity back into science.
I could fight misunderstanding with metaphor, boredom with wordplay.
Most importantly, I could make scientists as real as any figure in
a Chekhov story: human, vulnerable, full of error. . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . .  Sarah
Adler
B.A. (fine art) University of
California, Santa Cruz
Growing up
in northern California, I fell in love with the natural world at
an early age. I always wanted to be outside sneaking off in my
imagination surrounded by plants and animals. I was fortunate to
attend a Waldorf school for several years, which triggered my passion
for painting and drawing early on. Over the last ten years, my art
has consistently portrayed the beauty and complexity of nature. I
have always hoped to inspire others with my art to realize the
preciousness of the world around us and the importance of its
preservation. Once I heard about science illustration, I knew it
was the perfect combination of my interests in our environment as
well as my passion for its beauty. . . . . . . . . . . . . . . . . .
. . . . . . . . . . . . . . . . . . . . . .
. . . . . . . . . . . .
 Lauren Day Benson
B.A. (art and feminist studies) University of
California, Santa Cruz I have aspired
to be a scientific illustrator since high school when my teacher,
Leo Kenney, introduced scientific illustration as the perfect
synthesis of art and nature appreciation. My goal as a scientific
illustrator is to use artistic representation to communicate
scientific concepts and subjects to the public. My summer internship
is at the Sierra Nevada Research Institute (Scientific Visualization
Fellowship). Top | 
