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Can bedrock be broken by earthquake or volcano?

My bet is volcanoes can crack through bedrock.
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JoyfulSilence · 51-55, M
Well, rising magma and gases under high pressure put strain on rocks which causes fractures (earthquakes).

In fact, that is one way scientists can predict volcanic eruptions, by measuring seismic activity. As well as heat, gases, elevation changes, etc.

And earthquakes cause fractures that magma can fills in.

Like in Iceland, where a plume of rising heat and magma causes the crust to dome up, then crack, and spread. The cracks relieve pressure, like an opening soda bottle, which causes the gases to bubble and magma to erupt into the cracks, forming fissure eruptions.
Depends a bit how thick the crust is. Generally when magma is making its way thru the crust, it does a combination of cracking and melting the crust. Magma is hotter and less dense than the surrounding material, so it always exerts upwards force. The cracking is detected as many minor tremors. Sometimes the ground also rises inches or a few feet due to pressure of the magma prior to volcanic eruption.
I would think an earthquake can.
@MsSwan This s what Google says.

Yes, an earthquake can break bedrock, particularly if the rock is already weakened by existing cracks or faults. Strong earthquakes can fracture bedrock, leading to damage and contributing to hazards like rockslides in subsequent seismic events.
exchrist · 36-40
@MsSwan yes I’d seen that too
ArishMell · 70-79, M
@MsSwan It's really the other way round, for major earthquakes.

The fault or thrust-plane already exists, and the tremor is the vibration of one mass of rock suddenly sliding on the other. It will break rocks deposited on top if the "re-activated" fault has been stable for long enough for that to have happened

This type of slip is associated with continental collision: one crust plate sliding over the other (usually ocean floor plate subducting below a continent as along the Pacific coasts); and with crustal extension. In the latter the crust is being stretched and eventually cracks with one wall of the fault sliding down the other.

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Volcanoes as such cause fairly small local earthquakes as the rising magma pushes its way towards the surface, melting and cracking its way through the Crust as it does so.

However, the whole process is rather more complicated than that; depending for a start whether the volcano is above a plate subduction (e.g. the Pacific "Ring of Fire") or plate fracture (Mid-Atlantic ridge and the island of Iceland.)

Or rarer, is like Hawaii, considered to be a giant volcano atop a convection plume of magma under a Pacific floor Crust plate.
kodiac · 22-25, M
Fracking fractures everything

 
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