SOUNDING THE ALARM: Once an earthquake warning system detects a strong quake, the alert goes out. In this scenario, when a break of the San Andreas Fault south of the Bay Area creates a strong tremor, those in the most densely populated areas to the north would have more than half a minute to get ready.
Image: Illustration by Emily Cooper and Tom Whalen
In Brief
- Earthquake early-warning networks detect the earliest stages of an earthquake and sound an alarm to warn people of the danger. The alerts can provide tens of seconds of warning time.
- Most systems rely on the fact that an earthquake comes in two parts: a fast-moving, sudden jolt and a slower-moving wave that causes the great majority of the damage.
- A network of seismometers can quickly identify the earthquake’s epicenter, improve predictions of the earthquake’s magnitude and reduce the incidence of false alarms.
- These networks already exist in a number of countries around the world. A proposed system for California would protect individuals and businesses up and down the Golden State.
More In This Article
Earthquakes are unique in the pantheon of natural disasters in that they provide no warning at all before they strike. Consider the case of the Loma Prieta quake, which hit the San Francisco Bay Area on October 17, 1989, just as warm-ups were getting under way for the evening’s World Series game between the San Francisco Giants and the Oakland A’s. At 5:04 p.m., a sudden slip of the San Andreas Fault shook the region with enough force to collapse a 1.5-mile section of a double-decker freeway and sections of the Bay Bridge connecting Oakland with San Francisco. More than 60 people died.
Over the years scientists have hunted for some signal—a precursory sign, however faint—that would allow forecasters to pinpoint exactly where and when the big ones will hit, something that would put people out of harm’s way. After decades spent searching in vain, many seismologists now doubt whether such a signal even exists.
This article was originally published with the title Seconds Before the Big One.
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3 Comments
Add CommentNatural diasters are just par for the course of being the dominate species on the planet, and diasters of quakes, flooding, huricanes, tornadoes, and tsunami's are on the long list of things one wants to avoid. When Katrina devastated New Orleans leaving the city in ruins, the major problem was not just the warning of the effected population in the area; it was the evacuation of the people in the affected area. The San Francisco quake is small compared to the quake in Japan, but are we immune from such killer quakes? What would we do when we are hit with a killer 9 quake? How prepared are we for a natural disater of that magnititude or greater? What about Yellow Stone National Park? How good are early warning systems if you can't evacute the population is time to save as many lives as possible?
Reply | Report Abuse | Link to thisPerhaps the warnings could be even earlier if we used other natural indicators. There are a number of precursor and warning signs available. e.g. solar wind speed changes, solar flare activity, depletion of electrons in the ionosphere above the earthquake area, disturbed animal behavior, and electric and magnetic field changes at ground level.
Reply | Report Abuse | Link to thisThen, as you say, it's getting the info to the residents. Japan is a good example for civil preparedness - but they did not think BIG enough. And now the construction corruption at Fukushima is biting them hard.
Earthquake is another misconstrued phenomenon.
Reply | Report Abuse | Link to thisIf you have experienced an earthquake and do the following experiment you to will realize that it is the interaction of whats named magnetism and tone of sound that produces the movement of an earthquake. (not the scrunching of rock)
If you are rich or funded purchase a large crystal bowl and a cow or cattle magnet. This experiment will shock the pants off of you. If your poor like the rest of us find some one in sound therapy and get them to gong their bowl. They will want to show how they can change the tone of sound with their gonger. Having your turn hold the magnet in your fist and make circles in the bowl. As the tone changes there will be a point where raw energy is produced and the magnet will be jumping around in your hand.
No such thing as plate tectonics. A falt line, like the rock chip in your windshield is an aftermath!
The havoc and land movement of whats named Earthquake comes from a tone of sound interacting with the Earths Magnetic field.
Simply go out and dig holes, insert a listening device, record the tone of sound of a large quake. Once you have the tone pegged install these at strategic places around the globe. Monitoring sound as it approaches a damaging tone gives ample warning to a catastrophic Earthquake.
My science of this was relayed to Pacific Geo Science Centre and I understand that this filtered down to Stanford University. At Depth SAFOD Earth Scope
The results of this has the US government spending hundreds of millions for drilling.
A Drilling rig is active on the San Andreas Fault and the US gov has put aside hundreds of millions of dollars for drilling to take place along the Pacific Coast (three holes to be drilled on Vancouver Island).
At this time four holes have been drilled free of charge, complements of the US Gov.
I believe this technology is being held back untill such time as it can be perfected.
cbc.ca bruce voigt