<p>Black hole mergers lose respective rotational energy during a merger. I understand that the energy 'emitted' is scattered as gravitational 'energy' that can henceforth be detected by gravitational detectors billions of light years away. I understand that the amount of shockwave energy in stellar mass black hole mergers can be equivalent to the mass of a star such as the sun. So if two rapidly rotating SMBHs on the scale of SagA* merge, the emergy emitted is in the range of hundred thousands of solar masses...?</p>

<p>Either case that is a lot of energy. If a two, let's say, 10 solar mass black holes merge at 10 light years, what are the literal impact effects on a terrestrial planet in such adjacent system? </p>

<p>Barely sensable by its inhabitants? Significant seismic? sufficient to sharply increase volcanism? Agitating the surface to lava? Obliterate small moons or planets in to a large rapidly expanding cloud of interplanetary lahar?</p>

<p>Assume that every ten thousand or less years such merger occurs in the milky way galaxy? Could these mergers constitute existential risks?</p>

CC BY-SA 4.0
2019-09-01T23:59:20.867Z
a different but related question in Physics SE: [How would a passing gravitational wave look or feel?](https://physics.stackexchange.com/q/338912/83380)
uhoh
CC BY-SA 4.0
2019-09-02T17:27:32.020Z
I apologise if you already know this, but, as unintuitive as it is, the alleged gravitational waves are emitted whilst the bodies are still orbiting each other; not at the point of impact.
White Prime
<black-hole><astrophysics>
Is there a way to calculate how much damage black hole merger shockwaves inflict on nearby objects?
Khannea
# Is there a way to calculate how much damage black hole merger shockwaves inflict on nearby objects?

(Asked by: username_0 on 2019-09-01)

Black hole mergers lose respective rotational energy during a merger. I understand that the energy 'emitted' is scattered as gravitational 'energy' that can henceforth be detected by gravitational detectors billions of light years away. I understand that the amount of shockwave energy in stellar mass black hole mergers can be equivalent to the mass of a star such as the sun. So if two rapidly rotating SMBHs on the scale of SagA\* merge, the emergy emitted is in the range of hundred thousands of solar masses...?

Either case that is a lot of energy. If a two, let's say, 10 solar mass black holes merge at 10 light years, what are the literal impact effects on a terrestrial planet in such adjacent system?

Barely sensable by its inhabitants? Significant seismic? sufficient to sharply increase volcanism? Agitating the surface to lava? Obliterate small moons or planets in to a large rapidly expanding cloud of interplanetary lahar?

Assume that every ten thousand or less years such merger occurs in the milky way galaxy? Could these mergers constitute existential risks?

**Tags:** black-hole, astrophysics

> **Comments:**
> **username_1**: a different but related question in Physics SE: [How would a passing gravitational wave look or feel?](https://physics.stackexchange.com/q/338912/83380)  
> **username_2**: I apologise if you already know this, but, as unintuitive as it is, the alleged gravitational waves are emitted whilst the bodies are still orbiting each other; not at the point of impact.  

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## 0 answers

