{ "id": 93047, "title": "Know these seismic waves signaling an earthquake", "url": "/competitions/LANL-Earthquake-Prediction/discussion/93047", "author_name": "", "post_date": "2019-05-22T16:45:35.706917300Z", "votes": 17, "comment_count": 7, "views": 0, "content": "

Seismic waves : Seismic waves are the waves of energy caused by the sudden breaking of rock within the earth or an explosion. They are the energy that travels through the earth and is recorded on seismographs.

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Types : There are several different kinds of seismic waves, and they all move in different ways. The two main types of waves are body waves and surface waves. Body waves can travel through the earth's inner layers, but surface waves can only move along the surface of the planet like ripples on water. Earthquakes radiate seismic energy as both body and surface waves.

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Body waves : Traveling through the interior of the earth, body waves arrive before the surface waves emitted by an earthquake. These waves are of a higher frequency than surface waves.

\n\n

P Wave : The first kind of body wave is the P wave or primary wave. This is the fastest kind of seismic wave, and, consequently, the first to 'arrive' at a seismic station.\n\"\"

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S Wave : The second type of body wave is the S wave or secondary wave, which is the second wave you feel in an earthquake. An S wave is slower than a P wave.\n\"\"

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Surface Waves : Travelling only through the crust, surface waves are of a lower frequency than body waves, and are easily distinguished on a seismogram as a result. Though they arrive after body waves, it is surface waves that are almost enitrely responsible for the damage and destruction associated with earthquakes. This damage and the strength of the surface waves are reduced in deeper earthquakes.

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Love Waves : It's the fastest surface wave and moves the ground from side-to-side. Confined to the surface of the crust, Love waves produce entirely horizontal motion.\n\"\"

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Rayleigh Waves : A Rayleigh wave rolls along the ground just like a wave rolls across a lake or an ocean. Because it rolls, it moves the ground up and down, and side-to-side in the same direction that the wave is moving. Most of the shaking felt from an earthquake is due to the Rayleigh wave, which can be much larger than the other waves.\n\"\"

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Source : http://www.geo.mtu.edu/UPSeis/waves.html

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Edit 1: When the seismic waves reach a Piezoelectric sensor (shown below), a sensitive material present in the sensor gets deformed which generates voltage. \n\"\"

", "messages": [ { "id": "535308", "postDate": "05/22/2019 16:45:35", "content": "

Seismic waves : Seismic waves are the waves of energy caused by the sudden breaking of rock within the earth or an explosion. They are the energy that travels through the earth and is recorded on seismographs.

\n\n

Types : There are several different kinds of seismic waves, and they all move in different ways. The two main types of waves are body waves and surface waves. Body waves can travel through the earth's inner layers, but surface waves can only move along the surface of the planet like ripples on water. Earthquakes radiate seismic energy as both body and surface waves.

\n\n

Body waves : Traveling through the interior of the earth, body waves arrive before the surface waves emitted by an earthquake. These waves are of a higher frequency than surface waves.

\n\n

P Wave : The first kind of body wave is the P wave or primary wave. This is the fastest kind of seismic wave, and, consequently, the first to 'arrive' at a seismic station.\n\"\"

\n\n

S Wave : The second type of body wave is the S wave or secondary wave, which is the second wave you feel in an earthquake. An S wave is slower than a P wave.\n\"\"

\n\n

Surface Waves : Travelling only through the crust, surface waves are of a lower frequency than body waves, and are easily distinguished on a seismogram as a result. Though they arrive after body waves, it is surface waves that are almost enitrely responsible for the damage and destruction associated with earthquakes. This damage and the strength of the surface waves are reduced in deeper earthquakes.

\n\n

Love Waves : It's the fastest surface wave and moves the ground from side-to-side. Confined to the surface of the crust, Love waves produce entirely horizontal motion.\n\"\"

\n\n

Rayleigh Waves : A Rayleigh wave rolls along the ground just like a wave rolls across a lake or an ocean. Because it rolls, it moves the ground up and down, and side-to-side in the same direction that the wave is moving. Most of the shaking felt from an earthquake is due to the Rayleigh wave, which can be much larger than the other waves.\n\"\"

\n\n

Source : http://www.geo.mtu.edu/UPSeis/waves.html

\n\n

Edit 1: When the seismic waves reach a Piezoelectric sensor (shown below), a sensitive material present in the sensor gets deformed which generates voltage. \n\"\"

", "rawMarkdown": "**Seismic waves** : Seismic waves are the waves of energy caused by the sudden breaking of rock within the earth or an explosion. They are the energy that travels through the earth and is recorded on seismographs.\n\n**Types** : There are several different kinds of seismic waves, and they all move in different ways. The two main types of waves are body waves and surface waves. Body waves can travel through the earth's inner layers, but surface waves can only move along the surface of the planet like ripples on water. Earthquakes radiate seismic energy as both body and surface waves.\n\n**Body waves** : Traveling through the interior of the earth, body waves arrive before the surface waves emitted by an earthquake. These waves are of a higher frequency than surface waves.\n\n*P Wave* : The first kind of body wave is the P wave or primary wave. This is the fastest kind of seismic wave, and, consequently, the first to 'arrive' at a seismic station.\n![](http://www.geo.mtu.edu/UPSeis/images/P-wave_animation.gif)\n\n*S Wave* : The second type of body wave is the S wave or secondary wave, which is the second wave you feel in an earthquake. An S wave is slower than a P wave.\n![](http://www.geo.mtu.edu/UPSeis/images/S-wave_animation.gif)\n\n**Surface Waves** : Travelling only through the crust, surface waves are of a lower frequency than body waves, and are easily distinguished on a seismogram as a result. Though they arrive after body waves, it is surface waves that are almost enitrely responsible for the damage and destruction associated with earthquakes. This damage and the strength of the surface waves are reduced in deeper earthquakes.\n\n\n*Love Waves* : It's the fastest surface wave and moves the ground from side-to-side. Confined to the surface of the crust, Love waves produce entirely horizontal motion.\n![](http://www.geo.mtu.edu/UPSeis/images/Love_animation.gif)\n\n*Rayleigh Waves* : A Rayleigh wave rolls along the ground just like a wave rolls across a lake or an ocean. Because it rolls, it moves the ground up and down, and side-to-side in the same direction that the wave is moving. Most of the shaking felt from an earthquake is due to the Rayleigh wave, which can be much larger than the other waves.\n![](http://www.geo.mtu.edu/UPSeis/images/Rayleigh_animation.gif)\n\nSource : http://www.geo.mtu.edu/UPSeis/waves.html\n\nEdit 1: When the seismic waves reach a Piezoelectric sensor (shown below), a sensitive material present in the sensor gets deformed which generates voltage. \n![](https://upload.wikimedia.org/wikipedia/commons/c/c4/SchemaPiezo.gif)", "votes": null }, { "id": "535345", "postDate": "05/22/2019 18:14:07", "content": "

Awesome graphics. So, for real earthquakes, do people experience a combination of a love wave + rayleigh wave?

", "rawMarkdown": "Awesome graphics. So, for real earthquakes, do people experience a combination of a love wave + rayleigh wave?", "votes": null }, { "id": "535559", "postDate": "05/23/2019 06:42:03", "content": "

Nice visuals. Wish I didn't drop geology 201 back in the day. Thank you for recapping P and S waves. Hardly remember P and S waves other than the fact that one is faster than the other.

\n\n

Now I wonder if there is a way to extract these waves from acoustic readings. If I'm not mistaken acoustic_data is measured in voltage...

\n\n
\n

The seismic data is recorded using a piezoceramic sensor, which outputs a voltage upon deformation by incoming seismic waves. The seismic data of the input is this recorded voltage, in integers.

\n
\n\n

Quoting Bertrand from the discussion.

", "rawMarkdown": "Nice visuals. Wish I didn't drop geology 201 back in the day. Thank you for recapping P and S waves. Hardly remember P and S waves other than the fact that one is faster than the other. \n\nNow I wonder if there is a way to extract these waves from acoustic readings. If I'm not mistaken `acoustic_data` is measured in voltage... \n\n> The seismic data is recorded using a piezoceramic sensor, which outputs a voltage upon deformation by incoming seismic waves. The seismic data of the input is this recorded voltage, in integers.\n\nQuoting Bertrand from the discussion.", "votes": null }, { "id": "536115", "postDate": "05/24/2019 01:41:27", "content": "

So the Piezoelectric sensors are vertically oriented? I am very confused.

", "rawMarkdown": "So the Piezoelectric sensors are vertically oriented? I am very confused.", "votes": null }, { "id": "536582", "postDate": "05/24/2019 18:17:00", "content": "

As far as i remember(haven't work on the competition for a while), we do not deal with seismic waves here. The graphs, generated from the data, are not seismograms. They do not represent ground movements. They represent the acoustic emission recorded during the experiment. Something like- how noisy are the particles when move or/and break.

", "rawMarkdown": "As far as i remember(haven't work on the competition for a while), we do not deal with seismic waves here. The graphs, generated from the data, are not seismograms. They do not represent ground movements. They represent the acoustic emission recorded during the experiment. Something like- how noisy are the particles when move or/and break.", "votes": null }, { "id": "536586", "postDate": "05/24/2019 18:21:27", "content": "

I think \"Edit 1\" should be :\" When the acoustic waves reach the sensor...\"

", "rawMarkdown": "I think \"Edit 1\" should be :\" When the *acoustic* waves reach the sensor...\"", "votes": null }, { "id": "536599", "postDate": "05/24/2019 19:11:08", "content": "

That part was unclear to me too. I googled information about the sensor and as I remember, the sensor record the acoustic signal emitted when the grains in the experiment rearrange. I interpret that as \"how noisy is around there\" . If nothing moves, it will be quiet. When a force is applied and the grains start to rearrange, it will be noisy. \nThe data represents time periods before the failure. With that in mind, we can not extract P or S waves, because they do not exist yet. They start to radiate after the \"earthquake\" occurs.

", "rawMarkdown": "That part was unclear to me too. I googled information about the sensor and as I remember, the sensor record the acoustic signal emitted when the grains in the experiment rearrange. I interpret that as \"how noisy is around there\" . If nothing moves, it will be quiet. When a force is applied and the grains start to rearrange, it will be noisy. \nThe data represents time periods before the failure. With that in mind, we can not extract P or S waves, because they do not exist yet. They start to radiate after the \"earthquake\" occurs.", "votes": null }, { "id": "1849187", "postDate": "07/09/2022 09:35:45", "content": "

nice and well done!!

", "rawMarkdown": "nice and well done!!", "votes": null } ], "comments": [ { "id": 1849187, "author_name": "alirezakharazian", "author_url": "", "post_date": "07/09/2022 09:35:45", "content": "

nice and well done!!

", "votes": null, "replies": [] }, { "id": 535345, "author_name": "returnofsputnik", "author_url": "", "post_date": "05/22/2019 18:14:07", "content": "

Awesome graphics. So, for real earthquakes, do people experience a combination of a love wave + rayleigh wave?

", "votes": null, "replies": [] }, { "id": 535559, "author_name": "teeyee314", "author_url": "", "post_date": "05/23/2019 06:42:03", "content": "

Nice visuals. Wish I didn't drop geology 201 back in the day. Thank you for recapping P and S waves. Hardly remember P and S waves other than the fact that one is faster than the other.

\n\n

Now I wonder if there is a way to extract these waves from acoustic readings. If I'm not mistaken acoustic_data is measured in voltage...

\n\n
\n

The seismic data is recorded using a piezoceramic sensor, which outputs a voltage upon deformation by incoming seismic waves. The seismic data of the input is this recorded voltage, in integers.

\n
\n\n

Quoting Bertrand from the discussion.

", "votes": null, "replies": [ { "id": 536599, "author_name": "petya5q", "author_url": "", "post_date": "05/24/2019 19:11:08", "content": "

That part was unclear to me too. I googled information about the sensor and as I remember, the sensor record the acoustic signal emitted when the grains in the experiment rearrange. I interpret that as \"how noisy is around there\" . If nothing moves, it will be quiet. When a force is applied and the grains start to rearrange, it will be noisy. \nThe data represents time periods before the failure. With that in mind, we can not extract P or S waves, because they do not exist yet. They start to radiate after the \"earthquake\" occurs.

", "votes": null, "replies": [] } ] }, { "id": 536115, "author_name": "frankw", "author_url": "", "post_date": "05/24/2019 01:41:27", "content": "

So the Piezoelectric sensors are vertically oriented? I am very confused.

", "votes": null, "replies": [ { "id": 536582, "author_name": "petya5q", "author_url": "", "post_date": "05/24/2019 18:17:00", "content": "

As far as i remember(haven't work on the competition for a while), we do not deal with seismic waves here. The graphs, generated from the data, are not seismograms. They do not represent ground movements. They represent the acoustic emission recorded during the experiment. Something like- how noisy are the particles when move or/and break.

", "votes": null, "replies": [] } ] }, { "id": 536586, "author_name": "petya5q", "author_url": "", "post_date": "05/24/2019 18:21:27", "content": "

I think \"Edit 1\" should be :\" When the acoustic waves reach the sensor...\"

", "votes": null, "replies": [] } ], "raw_markdown_by_id": { "535308": "**Seismic waves** : Seismic waves are the waves of energy caused by the sudden breaking of rock within the earth or an explosion. They are the energy that travels through the earth and is recorded on seismographs.\n\n**Types** : There are several different kinds of seismic waves, and they all move in different ways. The two main types of waves are body waves and surface waves. Body waves can travel through the earth's inner layers, but surface waves can only move along the surface of the planet like ripples on water. Earthquakes radiate seismic energy as both body and surface waves.\n\n**Body waves** : Traveling through the interior of the earth, body waves arrive before the surface waves emitted by an earthquake. These waves are of a higher frequency than surface waves.\n\n*P Wave* : The first kind of body wave is the P wave or primary wave. This is the fastest kind of seismic wave, and, consequently, the first to 'arrive' at a seismic station.\n![](http://www.geo.mtu.edu/UPSeis/images/P-wave_animation.gif)\n\n*S Wave* : The second type of body wave is the S wave or secondary wave, which is the second wave you feel in an earthquake. An S wave is slower than a P wave.\n![](http://www.geo.mtu.edu/UPSeis/images/S-wave_animation.gif)\n\n**Surface Waves** : Travelling only through the crust, surface waves are of a lower frequency than body waves, and are easily distinguished on a seismogram as a result. Though they arrive after body waves, it is surface waves that are almost enitrely responsible for the damage and destruction associated with earthquakes. This damage and the strength of the surface waves are reduced in deeper earthquakes.\n\n\n*Love Waves* : It's the fastest surface wave and moves the ground from side-to-side. Confined to the surface of the crust, Love waves produce entirely horizontal motion.\n![](http://www.geo.mtu.edu/UPSeis/images/Love_animation.gif)\n\n*Rayleigh Waves* : A Rayleigh wave rolls along the ground just like a wave rolls across a lake or an ocean. Because it rolls, it moves the ground up and down, and side-to-side in the same direction that the wave is moving. Most of the shaking felt from an earthquake is due to the Rayleigh wave, which can be much larger than the other waves.\n![](http://www.geo.mtu.edu/UPSeis/images/Rayleigh_animation.gif)\n\nSource : http://www.geo.mtu.edu/UPSeis/waves.html\n\nEdit 1: When the seismic waves reach a Piezoelectric sensor (shown below), a sensitive material present in the sensor gets deformed which generates voltage. \n![](https://upload.wikimedia.org/wikipedia/commons/c/c4/SchemaPiezo.gif)", "535345": "Awesome graphics. So, for real earthquakes, do people experience a combination of a love wave + rayleigh wave?", "535559": "Nice visuals. Wish I didn't drop geology 201 back in the day. Thank you for recapping P and S waves. Hardly remember P and S waves other than the fact that one is faster than the other. \n\nNow I wonder if there is a way to extract these waves from acoustic readings. If I'm not mistaken `acoustic_data` is measured in voltage... \n\n> The seismic data is recorded using a piezoceramic sensor, which outputs a voltage upon deformation by incoming seismic waves. The seismic data of the input is this recorded voltage, in integers.\n\nQuoting Bertrand from the discussion.", "536115": "So the Piezoelectric sensors are vertically oriented? I am very confused.", "536582": "As far as i remember(haven't work on the competition for a while), we do not deal with seismic waves here. The graphs, generated from the data, are not seismograms. They do not represent ground movements. They represent the acoustic emission recorded during the experiment. Something like- how noisy are the particles when move or/and break.", "536586": "I think \"Edit 1\" should be :\" When the *acoustic* waves reach the sensor...\"", "536599": "That part was unclear to me too. I googled information about the sensor and as I remember, the sensor record the acoustic signal emitted when the grains in the experiment rearrange. I interpret that as \"how noisy is around there\" . If nothing moves, it will be quiet. When a force is applied and the grains start to rearrange, it will be noisy. \nThe data represents time periods before the failure. With that in mind, we can not extract P or S waves, because they do not exist yet. They start to radiate after the \"earthquake\" occurs.", "1849187": "nice and well done!!" }, "source": "meta" }