why is an earthquake accompanied with noise?
because vibration causes noises and in an earthquake, there is a lot of vibraion
Jacob is correct. In moderate earthquakes here in California, what I mainly hear is objects falling, pool water sloshing, furniture moving and the house joints creaking. However, weak earthquakes cannot be heard.
We had a magnitude 5.1 earthquake here in southern CA two days ago centered about 150 miles from my house. I could feel it but not hear it.
When I lived in southern California and there was an earthquake that occurred nearby, sometimes I heard a loud crack followed by the shaking and sometimes there was no initial sound but there was a drawn-out sound (like a train engine) that faded away as the shaking stopped. All that happens in a matter of seconds, usually. And it all depends on where you are in relation to the center of the earthquake, which directions the P waves and S waves are going, etc.
http://earthquake.usgs.gov/learning/listen/index.php
I highly recommend you listen to the sounds on this reference provided by Writeacher:
http://earthquake.usgs.gov/learning/listen/allsounds.php
I have heard these kinds of "crack" and "rumble" sounds on stronger earthquakes in the past. The crack is very distinct, but the rumble sound of the earth can be drowned out by the sounds of falling objects and shaking structures.
I read that it's the plates moving against each other that makes those "rumbling" sounds. I lived through a 6.+ earthquake and it sounded like hundreds of trains rolling by under the house.
The earth cracking (splitting apart) also makes noises.
An earthquake is often accompanied by noise due to several factors:
1. Source of the noise: The primary source of noise during an earthquake is the rock movement along the fault line. When stress builds up and eventually leads to a sudden release, the rocks fracture and slide against each other, generating intense vibrations. These vibrations produce both low-frequency sounds that can be heard and higher-frequency sounds that may not be audible to humans.
2. Rupture and ground vibrations: As the rocks break and slip, the sudden movement causes the ground to vibrate. This produces seismic waves that travel through the Earth's crust and generate a rumbling or roaring sound. Depending on the proximity to the epicenter and the intensity of the quake, this sound can range from a low rumble to a loud boom.
3. Collapsing structures: The shaking caused by an earthquake can cause buildings, infrastructure, and other objects to collapse or deform. The resulting crashes, creaks, and grinding sounds can contribute to the overall noise during an earthquake.
It's important to note that the noise associated with an earthquake might not always be audible in all situations. Factors like distance, depth, and local geological conditions can affect the sound's propagation and reach.
To get a more detailed understanding of the specific noise accompanying an earthquake, seismologists and scientists study seismic records and use specialized instruments called seismometers. These instruments measure and record the ground motion, allowing scientists to analyze the seismic waves generated by an earthquake and understand its characteristics, including the accompanying noise.