Another source of clean energy...

[birdguy 3,987]

Relatively speaking how large would a hole have to be drilled into the earth to be the equivalent of a catheter inserted into the vein of a human body?  Perhaps several miles in diameter?

Noel

Edited March 12, 2023 by birdguy

[martin-w 3,305]

14 hours ago, birdguy said:

A magnitude 3.4 earthquake is pretty mild.  Noy likely to cause any damage except maybe for a 100 year old outhouse in a run down condition.

It's hard to believe a 3.4 earthquake could cause several million dollars worth of danger.

Noel

 

Yeah, there was a 3.4 in the UK in 2019, Somerset, just shook a few houses. Wasn't a big deal. 

[dmwalker 614]

15 hours ago, birdguy said:

It's hard to believe a 3.4 earthquake could cause several million dollars worth of danger.

The damage was in the city of Basel in 2009:

"Geopower Basel had predicted some rock slippage during the project. Basel's location on top of a fault line – the upper Rhine trench – had been deliberately chosen because the heat was closer to the Earth's surface. However, Haering admitted the 3.4 magnitude earthquake was stronger than he had expected.

Geopower has already paid about 9m Swiss francs (£5.35m) in compensation for cracked walls and similar damage to nearby houses and other buildings.

Despite this and Haering's trial, the Swiss appetite for geothermal projects has not diminished.

Engineers started preliminary drilling in Zurich last month to see whether the area was suitable for a similar scheme, and St Gallen, in eastern Switzerland, plans to start work on its own geothermal project next year."

The project at St. Gallen was abandoned in 2014 because of tremors up to 3.5 magnitude, as well as for financial reasons.

I found several references to geothermal projects in France. One project in a suburb of Strasbourg sounded very optimistic but when I looked more closely, I found a statement:

"Suspension of all geothermal projects

After the seismic events that occurred in October 2019 and early December 2019 in the North of the Eurometropolis following the investigations carried out by Fonroche in Vendenheim, the Bas-Rhin Prefecture decided on December 9 to suspend all geothermal projects in progress. in the Lower Rhine.

The principle of precaution and protection of populations has thus been reaffirmed.

The project led by the company ES, with which the City maintains excellent relations and communicates in complete transparency, at the Innovation Park is therefore also at a standstill."

Edited March 13, 2023 by dmwalker

[birdguy 3,987]

There are plenty of natural geothermal sites being harvested for power and heat.  Are they also causing earthquakes?  Over thirty geothermal sites producing heat and power in the western United States.  https://en.wikipedia.org/wiki/List_of_geothermal_power_stations_in_the_United_States

I grew up in California so I am no stranger to earthquakes.  We take 3.4 quakes rather lightly.  I was also a seismic technician in the Airforce for a few years.

My Mom could sense an earthquake before we felt it.  I recall at dinner time one evening she suddenly sat up straight and said, "Earthquake!"  A minute later we felt it.

Perhaps in an area where earthquakes are rare a 3,4 might scare people.  But they seldom cause and damage and when they do it is minor.  Perhaps in aseismic areas a magnitude 3.4 might seem serious but it's pretty low.

Noel

 

[Mike A 356]

4 hours ago, birdguy said:

My Mom could sense an earthquake before we felt it.

I've been able to "hear" some earthquakes right before they hit.  It has to be relatively quiet otherwise, but about a couple seconds before it starts shaking, I've heard what seems like a sudden rush of wind on otherwise calm days.

[dave2013 1,174]

5 hours ago, birdguy said:

Over thirty geothermal sites producing heat and power in the western United States.

Sure, but the wells aren't 65,000 feet deep.  The Coso plant wells are 2-12 thousand feet.  I'm guessing that other geothermal wells are close to this depth as well.

The generation for these plants is also relatively small with the exception of The Geysers, Coso, and Imperial Valley plants in California which generate 1600, 430, and 270 MW respectively.  The nuclear plant that provides my power has a capacity of 1700MW.  Some of the bigger nuclear plants produce 2-3 times that.

Geothermal is great but so far is only viable in certain locations.  Of course we should take advantage of the almost free power, but it's currently only a small percentage of energy production.  I'm totally on board with expanding it where possible and where it can be done safely.  The article mentions a type of fracking, which I thought was a big "no no", but if it's labeled "green" then maybe it will get approved.

Dave

[martin-w 3,305]

15 hours ago, dave2013 said:

Sure, but the wells aren't 65,000 feet deep.

 

15 hours ago, dave2013 said:

Geothermal is great but so far is only viable in certain locations. 

 

Indeed, that was what I said in my previous post. Currently we chose sites that are geologically unstable areas, tectonic boundaries, because that's where geothermal energy is available, so earth tremors in geologically unstable boundaries, perhaps exacerbated by the drilling, isn't unexpected.

Quaise, if all goes well, will have the luxury of drilling anywhere, and moving away from those instabilities. No longer in use fossil fuel plants are the perfect locations, with steam generators already onsite. 

[martin-w 3,305]

21 hours ago, birdguy said:

My Mom could sense an earthquake before we felt it. 

 

16 hours ago, Mike A said:

I've been able to "hear" some earthquakes right before they hit.

 

When I was in the UK we had the occasional earth tremor. I recall one such tremor where something like you both claim may have been the case. 

I suddenly woke up from deep sleep. no idea why, then a few seconds later the earth tremor hit. Wardrobe door flung open and the whole house shook. My son then came into my bedroom and said the same, he woke up just before it struck. My daughter of course slept all the way through and had no idea it had happened. Once, our alarm system went off and the siren was outside her bedroom window, horrendous row... she slept straight through it. 😁

So what happened, did my son and I sense something? Or was their a tremor that woke us up, followed by an aftershock? Who knows. 

[birdguy 3,987]

There are two types of waves created by an earthquake.  P waves are vertical waves that travel in straight directions and bounce off the various discontinuities they encounter like the crust/mantle and the mantle/core.  They are less powerful and seldom felt and always arrive at a location ahead of the surface wave.

The surface wave is more powerful and is a transverse wave that travels along the surface of the earth and arrives at a location later than the P waves.  The surface wave is more readily felt and does the most damage.

It's possible that people who feel something before the earthquake (S waves) arrive are feeling the weak P waves that travel faster and arrive ahead of the S waves.

Perhaps this is why some people tuned to P waves feel earthquakes before most people do.

Noel

 

[Mace 1,988]

On 3/14/2023 at 10:16 AM, birdguy said:

There are two types of waves created by an earthquake.  P waves are vertical waves that travel in straight directions and bounce off the various discontinuities they encounter like the crust/mantle and the mantle/core.  They are less powerful and seldom felt and always arrive at a location ahead of the surface wave.

The surface wave is more powerful and is a transverse wave that travels along the surface of the earth and arrives at a location later than the P waves.  The surface wave is more readily felt and does the most damage.

It's possible that people who feel something before the earthquake (S waves) arrive are feeling the weak P waves that travel faster and arrive ahead of the S waves.

Perhaps this is why some people tuned to P waves feel earthquakes before most people do.

Noel

 

I think this may explain what I felt in a 5.x Richter earthquake in 1990.  

I was outside, standing perfectly still on the soil (in shoes) when it hit -- and the best way I can describe it would be as if someone took a plastic ruler and it snapped...followed by some residual shaking over the next couple of seconds, as if the ruler was swaying/vibrating after the initial snap.  Your description of the wave types made me wonder...the initial "snap" may have been the P waves, and the rest of it the S waves?

[birdguy 3,987]

That could have been Rhett.  P waves are vertical up and down motion while the S waves are horizontal side to side motions.  S waves are more readily felt than P waves.

Also the Richter scale is logarithmic.  A 5.9 earthquake is over 1,500 times stronger than a 3.9 earthquake.

In 1964 I was part of the crew at an Air Force recording station in Wyoming when the 9.2 earthquake hit Anchorage Alaska.  That quake and the aftershocks made our instruments unrecordable for a week.  The were maxing out.  A 9.2 earthquake has the equivalent power of 950 tons of TNT.

Noel