 under the surface. Red is 392 degrees Fahrenheit (200 Celsius). )
DRILLING HOT SPOTS: This map shows the estimated temperature of the ground 3.7 miles (6 kilometers) under the surface. Red is 392 degrees Fahrenheit (200 Celsius).
Image: WIKIMEDIA COMMONS/US DEPARTMENT OF ENERGY
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The Best Science Writing Online 2012
Showcasing more than fifty of the most provocative, original, and significant online essays from 2011, The Best Science Writing Online 2012 will change the way...
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Despite the promise of cheap, clean power, geothermal energy development may be on shaky ground. There have been rumblings from residents and scientists alike that drilling deep to tap naturally occurring heat could cause bigger earthquakes.
Already on edge about temblors, northern California locals are eying an expansive new geothermal project proposed by a company called AltaRock that's going to be boring down more than two miles (3.2 kilometers). The area near the town of Anderson Springs—about 90 miles (150 kilometers) north of San Francisco—is home to natural geothermal vents (nicknamed The Geysers by early visitors who saw the steam vents there) and has been exploited for its natural energy-generating capacity for the better part of the last century. Starting in the 1970s, as technology improved, engineers started to crank up the production levels. Small earthquakes began shortly thereafter.
Just a few years ago, a now-infamous geothermal project in Basel, Switzerland, which drilled three miles (4.8 kilometers) into Earth's crust, set off a magnitude 3.4 earthquake, rocking the town and shutting the operation down entirely, The New York Times recalled recently.
Drilling has even been fingered as the cause of a massive 2006 mud volcano in Java, which displaced more than 30,000 people after a gas exploration project went awry. "We are more certain than ever that the Lusi mud volcano is an unnatural disaster," Richard Davies of the Center for Research into Earth Energy Systems at Durham University in England said in a statement after investigating the incident.
The U.S. Department of Energy has already chipped in $36 million for AltaRock's project, and in an effort to drive down the price of renewable energy Google has anted up $6.25 million, the Times reported.
But will these deep holes—and deep-pocketed investors—trigger the next big one? To find out, we spoke with U.S. Geological Survey Earthquake Hazards Team seismologist David Oppenheimer, who is based in Menlo Park, Calif., just a couple hours south of the area.
[An edited transcript of the interview follows.]
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15 Comments
Add Commentany interference with our mother earth, like blasting deep underground, testing atomic devices at kilometers down, erasing hills , damming huge water masses, will surely interfere with the plates. it is a pity the survival tekniks of humans depend so much on just such and many other similar measures.
Reply | Report Abuse | Link to thisThey do not need to drill holes to build a geothermal plant in active volcanic areas. They can build a thermal power plant without drilling holes in active volcanic areas and use melted salt to heat up the water to push the turbines. Solar panels can heat the salt up during the day and get it hot enough to make it through the night. Save the drilling for non-active areas.
Reply | Report Abuse | Link to thisThe U.S. Department of Energy did **not** give AltaRock $36 million for its project.
Reply | Report Abuse | Link to thisIf you had read the NY Times article more carefully, you would have seen that it said,
"AltaRock, founded by Susan Petty, a veteran geothermal researcher, has secured more than $36 million from the Energy Department, several large venture-capital firms, including Kleiner Perkins Caufield & Byers, and Google."
You overlooked the private parties in the mix.
The breakdown for the $36 million is $4 million for startup (see http://earth2tech.com/2007/08/14/startup-altarock-raises-4m-geothermal/), $26.25 for a second round of investment (including $6.25 from Google--see http://altarockenergy.com/AltaRockEnergy.2008-08-19.pdf), and, finally, the DOE has "chipped in" another $6 million or so (see http://www.energy.gov/news/6624.htm).
Does anyone remember the note on the spray cans that said contents under pressure? We all know that if you punch a hole in something that is pressurized, the ingredient comes shooting out. Under some pressure if fountains but under extreme pressure the whole can blows up. The problem in tapping this kind of power is that there are all kinds of factors involved in estimating what kind of pressure is on the other end of the drill. The question is: Are we really that good at geology, math, and physics that we haven't had a major accident in thirty years or have we just been extremely lucky?
Reply | Report Abuse | Link to thisHow come drilling miles down in the ground for oil doesn't cause earthquakes and how come tunneling miles down in the ground for coal doesn't cause earthquakes and drilling miles down in the ground for natural gas doesn't cause earthquakes? It sounds like the coal, oil, and natural gas people want you to think that clean energy, like geothermal, is more dangerous than their filthy energy that has proven time and time again that it is the most dangerous thing on this planet and has killed more people and animals than anything else known to man. Can a single geothermal plant, if properly placed away from faults, cause more destruction than a single coal, oil, or natural gas plant? Nover in the life of this planet.
Reply | Report Abuse | Link to thisYou would think that any change in equilibrium--being either from diminution of pressure or removal or placement of overburden--would change the local isostatic dynamics and result in minor earthquakes, but the massive use of geothermal energy over the long run would most likely have the effect of decreasing earthquakes since energy would be diverted from tectonic expression into generating electric power.
Reply | Report Abuse | Link to thisJames Davis, it isn't the drilling that causes quakes at issue here -- this interview doesn't make that entirely clear -- it's pumping fluids under pressure down wells that does. And, in fact, hydraulic fracturing is done fairly routinely now for enhanced recovery of oil and gas, when the formation that bears them is "tight" and doesn't easily give up its hydrocarbons. Then -- guess what -- you get quakes, just like are expected in the AltaRock experiment.
Reply | Report Abuse | Link to thisAnd coal operations do cause quakes when something bad happens, like the multiple and fatal collapses last year of the Crandall Mine in Utah.
naturopath1, there have been "blow outs" of all kinds of wells -- oil, gas, geothermal. There are regulations in place, both federal and state, to avoid this kind of problem, which is usually caused by careless operators. This is a well understood issue in geothermal, and decades of experience can safely address them.
And problems can happen in geothermal when you get oil and gas folks coming in, treating geothermal wells like they were oil and gas wells. This probably accounts for some of the problems with the Geodynamics project in Australia.
With this kind of geothermal -- creating a reservoir by easing open existing small fractures and making some small new ones, too -- downhole pressures likely won't be an issue, and pumps will be needed to get the hot water up to the surface.
JamesDavis asks: "How come drilling miles down in the ground for oil doesn't cause earthquakes and how come tunneling miles down in the ground for coal doesn't cause earthquakes and drilling miles down in the ground for natural gas doesn't cause earthquakes?"
Reply | Report Abuse | Link to thisI'm not a geologist, but a logical answer seems to be that oil and gas deposits form in structures (domes, usually) that are fairly free of tectonic movements and faults, because if the surrounding rock were fractured the deposit would escape or become too dispersed for recovery.
As for coal I don't believe there are many -- if any -- very deep coal mines. Coal isn't valuable enough to justify the expensive extraction inherent in a deep mine. They can cause tectonic-like events though -- witness the coal mine disaster in WV a few years ago when some pillars holding up the ceiling of the mine collapsed. The resulting tremor was first thought to be a natural earthquake. But these are small, local events not associated with existing faults.
I had earlier commented,some 2 years back,that deep drilling for not only geothermal energy,but also for oil and gas can trigger earthquakes ,since the overburden pressures are released,and the equilibrium is affected,triggering earthquakes.Some of the off shore oil well in the gulf region,Alaska,N.Sea and Mexico region are near fault zones,and the drilling for oil may now go as deep as 1-2 kilometers.That can not only disturb the equilibrium of pressures in the region,but also affect the hydrate deposits ,tiny ice crystals that store methane under pressure,in the cold depths of the sea.These deposits can explode like gas cylinders and trigger sea floor collapse ,thus accentuating the shocks from deep drilling.That definitely can trigger earthquakes.At the time when I had initially proposed this I had received letters from many experts discounting the possibilities.But now that has become apparent.Such hydrate explosions can also cause climate change problems from release of methane in large quantities to the atmosphere.
Reply | Report Abuse | Link to thisSURESHKUMAR.S,SCIENTIST AND ADVISER,NIIST,TRIVANDRUM,CSIR
Simple physics and geology here: Earthquake intensity or seismicity is dependent on fault size. Small active faults can produce no larger than small earthquakes; large active faults can produce up to large earthquakes. The Geysers area contains small active and inactive faults, no large faults. Do the math. Also, the San Andreas is 40 miles away... Involvment of the San Andreas from activity at The Geysers is like expecting your neighbor, who lives down the block with their windows closed, to wake up at night from your snoring.
Reply | Report Abuse | Link to thisIs the subject of geothermal different from geo-exchange?
Reply | Report Abuse | Link to thisWhy yes it is.
Reply | Report Abuse | Link to thisHow could the water which seeped inside produce an earthquake?
Reply | Report Abuse | Link to thisEarthquake is caused due to the movement of the land is a myth. The most important thing that is missing in this view is that there is no explanation for why earthquake occurs in the centre of the land instead of the peripheral area.
Actually the land is rising in different places. This is the reason why earthquakes occur only in the central parts of the land.
To be specific, after an earthquake occurred on September 30th of 1993, in the village named Killari, it was found that the land had risen about three feet in height.
This shows that the rise of the land is the cause of the earthquake.
Earthquake is the effect of the rise of the land
On September 30th 1993, the earthquake that hit the village, killari, situated in central part of India resulted in the death of more than eight thousand people and raised the land surface about three feet high.
This elevation was seen in an area of around two kilometers.
Why did the earthquake occur?
The quake occurred only in killari, situated in central India and left two kilometers of land area raised. This proves that the earthquake occurred only due to the rise of the land.
Apart from this, the pictures taken by the satellite before the quake showed that the temperature of killari had also risen and the pictures taken after the quake showed it to be normal.
After the earthquake occurred, on the borders of Andhra and Karnataka white colored smoke emitted from the ground.
Why did the land rise? Why was the temperature more? Why did the land emit white colored smoke?
We know that the molten rock material called magma is found inside the earth as we have seen it coming out through volcanoes.
In the same way, when the molten rock, lava flows on the earths surface, we can see the condensed steam and other gases in the form of white colored smoke.
As the water and other hot gases are eliminated as steam, the molten rock cools down and turned in to rock.
In the same way when the molten rock inside the earth starts cooling, water and
Other hot gases come out in the form of white smoke. Due to this, the temperature of the land rises.
Moreover when the molten rock cools and as the water and hot gases get released, the rocky plates that are formed are of less thickness.
For example: water has a higher density and the ice cubes formed from it have a lower density and float on water.
Likewise, the molten rock material which has a higher density produces rocky plates which have a lower density and move above the level of the molten rock.
In the same way, when new plates are produced by the molten rock material, they start moving upwards there by pushing the plates which were already formed. On account of this movement, the edges of the plates rub against each other thereby causing earthquakes.
For example, in 1356 an earthquake occurred in the city Basel in Switzerland which is situated in central Europe .
In the same city, an organization which produces electricity using the heat from underground, drilled two holes of five meters each on the earth in the year 2006.
The project was to send cold water through the first hole which would be changed into steam using the heat of the molten rock and pushed out through the second hole and by rotating dynamos; this would be converted into electricity.
But, on the eighth day after the water was sent inside the earth, in the same place, the Richter scale recorded an earthquake with an intensity of 3.4.
Even if atom bombs are tested underground, earthquakes do not occur. How could the water which seeped inside produce an earthquake?
This clearly shows that the water which seeped inside the earth cooled the molten rock which in turn formed new plates that rose up and caused the earthquake.
Yours faithfully,
Scientist, g.ponmudi,
chennai.
How could the water which seeped inside produce an earthquake?
Reply | Report Abuse | Link to thisEarthquake is caused due to the movement of the land is a myth. The most important thing that is missing in this view is that there is no explanation for why earthquake occurs in the centre of the land instead of the peripheral area.
Actually the land is rising in different places. This is the reason why earthquakes occur only in the central parts of the land.
To be specific, after an earthquake occurred on September 30th of 1993, in the village named Killari, it was found that the land had risen about three feet in height.
This shows that the rise of the land is the cause of the earthquake.
Earthquake is the effect of the rise of the land
On September 30th 1993, the earthquake that hit the village, killari, situated in central part of India resulted in the death of more than eight thousand people and raised the land surface about three feet high.
This elevation was seen in an area of around two kilometers.
Why did the earthquake occur?
The quake occurred only in killari, situated in central India and left two kilometers of land area raised. This proves that the earthquake occurred only due to the rise of the land.
Apart from this, the pictures taken by the satellite before the quake showed that the temperature of killari had also risen and the pictures taken after the quake showed it to be normal.
After the earthquake occurred, on the borders of Andhra and Karnataka white colored smoke emitted from the ground.
Why did the land rise? Why was the temperature more? Why did the land emit white colored smoke?
We know that the molten rock material called magma is found inside the earth as we have seen it coming out through volcanoes.
In the same way, when the molten rock, lava flows on the earth’s surface, we can see the condensed steam and other gases in the form of white colored smoke.
As the water and other hot gases are eliminated as steam, the molten rock cools down and turned in to rock.
In the same way when the molten rock inside the earth starts cooling, water and
Other hot gases come out in the form of white smoke. Due to this, the temperature of the land rises.
Moreover when the molten rock cools and as the water and hot gases get released, the rocky plates that are formed are of less thickness.
For example: water has a higher density and the ice cubes formed from it have a lower density and float on water.
Likewise, the molten rock material which has a higher density produces rocky plates which have a lower density and move above the level of the molten rock.
In the same way, when new plates are produced by the molten rock material, they start moving upwards there by pushing the plates which were already formed. On account of this movement, the edges of the plates rub against each other thereby causing earthquakes.
For example, in 1356 an earthquake occurred in the city Basel in Switzerland which is situated in central Europe .
In the same city, an organization which produces electricity using the heat from underground, drilled two holes of five meters each on the earth in the year 2006.
The project was to send cold water through the first hole which would be changed into steam using the heat of the molten rock and pushed out through the second hole and by rotating dynamos; this would be converted into electricity.
But, on the eighth day after the water was sent inside the earth, in the same place, the Richter scale recorded an earthquake with an intensity of 3.4.
Even if atom bombs are tested underground, earthquakes do not occur. How could the water which seeped inside produce an earthquake?
This clearly shows that the water which seeped inside the earth cooled the molten rock which in turn formed new plates that rose up and caused the earthquake.
Yours faithfully,
Scientist, g.ponmudi,
chennai.
It is true that drilling can relieve stress on the tectonic plates and allow for shifting. Therefore it may be advisable to drill in more stable areas. For example the Canadian shield is made of granite. The benefit for the area will be lower electrical prices, a further benefit is the elimination of the carbon footprint. Now for the areas that are in more active areas the power can be transmitted through more conventional means. Nuclear power is done the same way. Also with drilling being done slowly that may allow the Earth to adjust. Mankind has been blowing up bombs under the surface of the Earth and drilling for fossil fuels for decades. We need to be responsible for the safety of the Earth. Drill responsibly and carefully in more stable areas.
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