Gravity - just pure plain GRAVITY

[sucahyo]

Geothermal heat exraction can not possibly cause earthquakes.

It is not direct effect, not caused by utilization of heat. But instead by man made vibration either by deepening the hole or by vibration caused by heated liquid.

All they need to do is to chanel a pipe from surface down to the level where earth temperature is >250 degree C (Depends onthe exact plant design) then back up to surface. Normal water is pumped down through series of one-way valves. At bottom the water is heated and run through pipe back to the surface as steam, under pressure. This is completley closed structure. That is then used to turn the turbines, cooled down and pumped downwards again.

Compare: Can the waterpipe in your home cause your whole house to colapse? We are talking of proabbaly a 30cm pipe into a unstable geological formation that covers few hundred square kilometers.

It is not caused by the hole, but by vibration. Is it possible to dug very deep to area near a volcano without using device that cause vibration? Would the pipe guaranteed to be vibration free, it won't be slow velocity fluid isn't it?

Trickling a high pressure balance can cause it to shift. A small vibration at the center of the earth may not felt by the human on the surface, but have the chance to cause the earth to enhance it many time if it is by chance hit correct vibration.

There is a story where earthquake is following a blast of dynamite in earth surface in days or hours. Is it that impossible for vibration near the center of pressure to cause periodic earthquake?

Only issue is: Geothermal plants are only possible in locations where there is strong geological upheavels and that usually goes hand in hand with geological unstability - earth tremors and quakes

Yes, broken pipe caused by land movement is a big problem too. It may be the hidden big maintenance cost for that.

Natural underground pressure that has been building up over past centuries. Normally Indonesia is prone to MAJOR volcanic erruptions; as such it has been a very long time overdue. I am not talking of the small cooking fires going on at present.

Add to this resonance from human activity - and I can feel bad vibes.

Yes, that is my point. guitar string sound louder in front of the resonant box. Very small vibration near the center of the pressure might trigger it much more effectively that big explosion at earth surface.