A seismogram is a graph output by a seismograph. It is a record of the ground motion at a measuring station as a function of time. Seismograms typically record motions in three cartesian axes (x, y, and z), with the z axis perpendicular to the Earth's surface and the x- and y- axes parallel to the surface. The energy measured in a seismogram may result from an earthquake or from some other source, such as an explosion. Seismograms can record lots of things, and record many little waves, called microseisms. These tiny microseisms can be caused by heavy traffic near the seismograph, waves hitting a beach, the wind, and any number of other ordinary things that cause some shaking of the seismograph.
Historically, seismograms were recorded on paper attached to rotating drums. Some used pens on ordinary paper, while others used light beams to expose photosensitive paper. Today, practically all seismograms are recorded digitally to make analysis by computer easier. Some drum seismometers are still found, especially when used for public display. Seismograms are essential for finding the location and magnitude of earthquakes.
How to learn about the occurrence of an earthquake by analyzing the seismogram recordings of the seismic waves.
Download the Reference Table here: https://bit.ly/3ctUaX1 Additional science videos and resources at: https://science.glide.page
Subscribe to my channel: https://www.youtube.com/user/mikesammartano?sub_confirmation=1
published: 28 Dec 2013
Seismograph
published: 22 Aug 2019
Seismograph
published: 12 Dec 2022
3-component Seismograms—Capturing the motion of an earthquake. (Educational)
www.iris.edu/earthquake for more animations.
Modern seismometers include 3 elements to determine the simultaneous movement in 3 directions: up-down, north-south,and east-west. Each direction of movement gives information about the earthquake. This animation shows both the movement of the three basic waves (P, S, and surface) and the effect of the waves on a building. The three seismograms produced by a modern seismograph station show that the P wave is more visible on the vertical component and the S wave amplitude is larger on the horizontal components.
We emphasize that seismic waves traveling away from an earthquake occur everywhere, not just at seismic stations.
Reviewed and narrated by Wendy Bohon, Informal education specialist, Incorporated Research Institutions for Seismology.
An...
published: 15 Mar 2017
How a Seismograph Works
How a Seismograph Works
This video is part of a free science course for homeschool students. The labsheets, textbooks, quizzes, and other materials can be accessed 100% free of charge at http://www.HandsomeScienceTeacher.com
Mr. Bertoch covers your entire science curriculum.
Hundreds of articles
Hundreds of videos
Hands-on Labs
All laid out in on a week-by-week easy to follow plan.
Totally Free!
published: 25 Apr 2012
California Seismograph Live Earthquake News
...
Buy us a coffee here: https://bmc.link/caseismograph
Permanent URL: YouTube.com/caseismograph/live
Click here 4 Sales: https://caseismograph.com/
CaSei-G7: https://docs.google.com/spreadsheets/d/1kqkp3EwDfalhEF3rxnLExrSWL3z0CDH1NfuTgxrg5JY/edit?usp=sharing
An explanation of the abbreviations can be found at the bottom of this page.
Please read the description of this feed below. This will greatly help you understand what you are seeing on this YouTube Live site.
Welcome, CaSeismograph is the only featured self-made physical seismograph drum internet live feed in the world! We strive to create a live feed that will serve Southern California people giving everyone a chance to communicate and exchange information about local earthquakes and fu...
published: 18 Sep 2024
How to Read a Seismogram
This video reviews how to read a seismogram and determine its magnitude.
Created by:
Kiersti Ford, MS, PG
[email protected]
published: 17 Feb 2021
Vertical Seismograph
Animation of the principles of a drum-style vertical seismograph station that records up-and-down movement. Seismographs are designed so that slight earth vibrations move the instrument. The suspended mass remains at rest as the spring absorbs some of the motion. The stylus (pen) affixed to the mass, records the relative motion between itself and the rest of the instrument, thus recording the ground motion.
More Info at:
http://www.iris.edu/hq/programs/education_and_outreach/aotm/8
published: 06 Nov 2008
SEISMIC WAVES | Easy Physics Animation
What is a Seismic Wave?
What happens if you disturb the water of a calm pond?
Yes exactly!
When you disturb the water, it will continuously produce ripples or waves.
Just like in an earthquake, the sudden movement of the underground rocks produces energy waves that moves the Earth’s surface.
These waves are called Seismic Waves. These waves could travel through and on the surface that cause the shaking and vibrations of the ground.
There are 2 types of Seismic waves: Body waves and Surface Waves.
Basically body waves are waves that travel through the Earth’s inner layer. And while Surface waves are waves that can ONLY travel through the surface layer, making the Body waves travel faster than the surface waves. However, surface waves causes more damage than the body waves.
Now the...
How to learn about the occurrence of an earthquake by analyzing the seismogram recordings of the seismic waves.
Download the Reference Table here: https://bit....
How to learn about the occurrence of an earthquake by analyzing the seismogram recordings of the seismic waves.
Download the Reference Table here: https://bit.ly/3ctUaX1 Additional science videos and resources at: https://science.glide.page
Subscribe to my channel: https://www.youtube.com/user/mikesammartano?sub_confirmation=1
How to learn about the occurrence of an earthquake by analyzing the seismogram recordings of the seismic waves.
Download the Reference Table here: https://bit.ly/3ctUaX1 Additional science videos and resources at: https://science.glide.page
Subscribe to my channel: https://www.youtube.com/user/mikesammartano?sub_confirmation=1
www.iris.edu/earthquake for more animations.
Modern seismometers include 3 elements to determine the simultaneous movement in 3 directions: up-down, north-south...
www.iris.edu/earthquake for more animations.
Modern seismometers include 3 elements to determine the simultaneous movement in 3 directions: up-down, north-south,and east-west. Each direction of movement gives information about the earthquake. This animation shows both the movement of the three basic waves (P, S, and surface) and the effect of the waves on a building. The three seismograms produced by a modern seismograph station show that the P wave is more visible on the vertical component and the S wave amplitude is larger on the horizontal components.
We emphasize that seismic waves traveling away from an earthquake occur everywhere, not just at seismic stations.
Reviewed and narrated by Wendy Bohon, Informal education specialist, Incorporated Research Institutions for Seismology.
Animated by Jenda Johnson, Earth Sciences Animated.
Reviewed by Danielle Sumy, Incorporated Research Institutions for Seismology.
Made possible by support from the National Science Foundation.
Music: “On the Passing of Time”, Kevin MacLeod.
www.iris.edu/earthquake for more animations.
Modern seismometers include 3 elements to determine the simultaneous movement in 3 directions: up-down, north-south,and east-west. Each direction of movement gives information about the earthquake. This animation shows both the movement of the three basic waves (P, S, and surface) and the effect of the waves on a building. The three seismograms produced by a modern seismograph station show that the P wave is more visible on the vertical component and the S wave amplitude is larger on the horizontal components.
We emphasize that seismic waves traveling away from an earthquake occur everywhere, not just at seismic stations.
Reviewed and narrated by Wendy Bohon, Informal education specialist, Incorporated Research Institutions for Seismology.
Animated by Jenda Johnson, Earth Sciences Animated.
Reviewed by Danielle Sumy, Incorporated Research Institutions for Seismology.
Made possible by support from the National Science Foundation.
Music: “On the Passing of Time”, Kevin MacLeod.
How a Seismograph Works
This video is part of a free science course for homeschool students. The labsheets, textbooks, quizzes, and other materials can be acce...
How a Seismograph Works
This video is part of a free science course for homeschool students. The labsheets, textbooks, quizzes, and other materials can be accessed 100% free of charge at http://www.HandsomeScienceTeacher.com
Mr. Bertoch covers your entire science curriculum.
Hundreds of articles
Hundreds of videos
Hands-on Labs
All laid out in on a week-by-week easy to follow plan.
Totally Free!
How a Seismograph Works
This video is part of a free science course for homeschool students. The labsheets, textbooks, quizzes, and other materials can be accessed 100% free of charge at http://www.HandsomeScienceTeacher.com
Mr. Bertoch covers your entire science curriculum.
Hundreds of articles
Hundreds of videos
Hands-on Labs
All laid out in on a week-by-week easy to follow plan.
Totally Free!
...
Buy us a coffee here: https://bmc.link/caseismograph
Permanent URL: YouTube.com/caseismograph/live
Click here 4 Sales: https://caseism...
...
Buy us a coffee here: https://bmc.link/caseismograph
Permanent URL: YouTube.com/caseismograph/live
Click here 4 Sales: https://caseismograph.com/
CaSei-G7: https://docs.google.com/spreadsheets/d/1kqkp3EwDfalhEF3rxnLExrSWL3z0CDH1NfuTgxrg5JY/edit?usp=sharing
An explanation of the abbreviations can be found at the bottom of this page.
Please read the description of this feed below. This will greatly help you understand what you are seeing on this YouTube Live site.
Welcome, CaSeismograph is the only featured self-made physical seismograph drum internet live feed in the world! We strive to create a live feed that will serve Southern California people giving everyone a chance to communicate and exchange information about local earthquakes and future events. As you can imagine, this endeavor is quite an undertaking and we thank you for your support as we look forward to daily growing and informing people of earthquake activity in the SOCAL area.
CaSeismograph is for the young and old, and everyone in between. We desire to keep CaSeismograph a child-friendly place and as scientific and accurate in all aspects. This is why our chat is moderated and we expect the chat users to follow the CaSeismograph Team rules. Please be courteous so everyone will undoubtedly have an enjoyable time.
For more in-depth information on our site, please click here:
https://raspberryshake.org/news/southern-california-live-seismic-activity-on-youtube/
All Physical seismographs, earthquake graphics, images, background, content, video, voice content captured in this live feed are the property of CaSeismograph, and are NOT intended for redistribution, copying, or repeating unless otherwise approved in writing by the content creator, CaSeismograph on YouTube.
CaSeismograph owns the RS Seismograph in Escondido (https://raspberryshake.org/) Our Temescal Valley sensor is displayed by one of our CaSeismograph members and can be found at the Community Station View page of the https://raspberryshake.org/ site.
Please subscribe and share with friends and family. For any questions or inquiries, you may contact CaSeismograph at [email protected].
Thank you!
- The CaSeismograph Team.
Abbreviations: GG = Garden Grove
GMS = Ground Motion Sensor
H = Horizontal
N = North
E = East
S = South
W = West
SMS = Surface Motion Sensor
V = Vertical
CNS = Current Needle Sensitivity
CNT = Current Needle Tracking
CDS = Current Drum Speed
SDR = Single Drum Revolution
LS = Line Speed
LW= Line Width
The white X on RS map = location of the drum and e-Graph
Daytime CNS settings should be between 1000-1500. If/when the CNS setting is over 1550, the needle movement can turn the paper black. Most of the daytime needle movement is caused by urban noise. Earthquakes are still visible during high CNS settings because they overpower the smaller needle movement caused by traffic/construction. Examples of earthquake signatures made by our drums / e-Graphs, click here: https://www.youtube.com/c/CaSeismograph/videos
CaSeismograph has proprietary rights to all content displayed on the CaSeismograph live site.
The Raspberryshake map and RS stations are displayed with the full consent of Raspberryshake.
The EQ list is composed of public domain information found at:
https://scedc.caltech.edu/recent/Quakes/quakes0.html and
https://www.emsc-csem.org/Earthquake/world/
There are currently three hand-picked RS stations we believe to have very well-located RS
geophone sensors. We have displayed them as a guest on our site and would like to get in contact with either one of the owners. Please contact us at [email protected] and we would love to speak to you about officially supporting your RS sensor with credit to your name on our channel.
If you are having a life-threatening emergency, please disconnect and dial 911.
...
Buy us a coffee here: https://bmc.link/caseismograph
Permanent URL: YouTube.com/caseismograph/live
Click here 4 Sales: https://caseismograph.com/
CaSei-G7: https://docs.google.com/spreadsheets/d/1kqkp3EwDfalhEF3rxnLExrSWL3z0CDH1NfuTgxrg5JY/edit?usp=sharing
An explanation of the abbreviations can be found at the bottom of this page.
Please read the description of this feed below. This will greatly help you understand what you are seeing on this YouTube Live site.
Welcome, CaSeismograph is the only featured self-made physical seismograph drum internet live feed in the world! We strive to create a live feed that will serve Southern California people giving everyone a chance to communicate and exchange information about local earthquakes and future events. As you can imagine, this endeavor is quite an undertaking and we thank you for your support as we look forward to daily growing and informing people of earthquake activity in the SOCAL area.
CaSeismograph is for the young and old, and everyone in between. We desire to keep CaSeismograph a child-friendly place and as scientific and accurate in all aspects. This is why our chat is moderated and we expect the chat users to follow the CaSeismograph Team rules. Please be courteous so everyone will undoubtedly have an enjoyable time.
For more in-depth information on our site, please click here:
https://raspberryshake.org/news/southern-california-live-seismic-activity-on-youtube/
All Physical seismographs, earthquake graphics, images, background, content, video, voice content captured in this live feed are the property of CaSeismograph, and are NOT intended for redistribution, copying, or repeating unless otherwise approved in writing by the content creator, CaSeismograph on YouTube.
CaSeismograph owns the RS Seismograph in Escondido (https://raspberryshake.org/) Our Temescal Valley sensor is displayed by one of our CaSeismograph members and can be found at the Community Station View page of the https://raspberryshake.org/ site.
Please subscribe and share with friends and family. For any questions or inquiries, you may contact CaSeismograph at [email protected].
Thank you!
- The CaSeismograph Team.
Abbreviations: GG = Garden Grove
GMS = Ground Motion Sensor
H = Horizontal
N = North
E = East
S = South
W = West
SMS = Surface Motion Sensor
V = Vertical
CNS = Current Needle Sensitivity
CNT = Current Needle Tracking
CDS = Current Drum Speed
SDR = Single Drum Revolution
LS = Line Speed
LW= Line Width
The white X on RS map = location of the drum and e-Graph
Daytime CNS settings should be between 1000-1500. If/when the CNS setting is over 1550, the needle movement can turn the paper black. Most of the daytime needle movement is caused by urban noise. Earthquakes are still visible during high CNS settings because they overpower the smaller needle movement caused by traffic/construction. Examples of earthquake signatures made by our drums / e-Graphs, click here: https://www.youtube.com/c/CaSeismograph/videos
CaSeismograph has proprietary rights to all content displayed on the CaSeismograph live site.
The Raspberryshake map and RS stations are displayed with the full consent of Raspberryshake.
The EQ list is composed of public domain information found at:
https://scedc.caltech.edu/recent/Quakes/quakes0.html and
https://www.emsc-csem.org/Earthquake/world/
There are currently three hand-picked RS stations we believe to have very well-located RS
geophone sensors. We have displayed them as a guest on our site and would like to get in contact with either one of the owners. Please contact us at [email protected] and we would love to speak to you about officially supporting your RS sensor with credit to your name on our channel.
If you are having a life-threatening emergency, please disconnect and dial 911.
Animation of the principles of a drum-style vertical seismograph station that records up-and-down movement. Seismographs are designed so that slight earth vibra...
Animation of the principles of a drum-style vertical seismograph station that records up-and-down movement. Seismographs are designed so that slight earth vibrations move the instrument. The suspended mass remains at rest as the spring absorbs some of the motion. The stylus (pen) affixed to the mass, records the relative motion between itself and the rest of the instrument, thus recording the ground motion.
More Info at:
http://www.iris.edu/hq/programs/education_and_outreach/aotm/8
Animation of the principles of a drum-style vertical seismograph station that records up-and-down movement. Seismographs are designed so that slight earth vibrations move the instrument. The suspended mass remains at rest as the spring absorbs some of the motion. The stylus (pen) affixed to the mass, records the relative motion between itself and the rest of the instrument, thus recording the ground motion.
More Info at:
http://www.iris.edu/hq/programs/education_and_outreach/aotm/8
What is a Seismic Wave?
What happens if you disturb the water of a calm pond?
Yes exactly!
When you disturb the water, it will continuously produce ripples ...
What is a Seismic Wave?
What happens if you disturb the water of a calm pond?
Yes exactly!
When you disturb the water, it will continuously produce ripples or waves.
Just like in an earthquake, the sudden movement of the underground rocks produces energy waves that moves the Earth’s surface.
These waves are called Seismic Waves. These waves could travel through and on the surface that cause the shaking and vibrations of the ground.
There are 2 types of Seismic waves: Body waves and Surface Waves.
Basically body waves are waves that travel through the Earth’s inner layer. And while Surface waves are waves that can ONLY travel through the surface layer, making the Body waves travel faster than the surface waves. However, surface waves causes more damage than the body waves.
Now there are 2 types of body waves.
The Primary Waves and the Secondary Waves.
Enjoy this video about Seismic Waves.
#SeismicWaves #Physics #EducationalVideo
CONTACT US
Email: [email protected]
Facebook Page: https://www.facebook.com/EarthPen
Youtube Channel: https://www.youtube.com/channel/UCX1Hh7CvEc3RCUd4NRBWJMw
What is a Seismic Wave?
What happens if you disturb the water of a calm pond?
Yes exactly!
When you disturb the water, it will continuously produce ripples or waves.
Just like in an earthquake, the sudden movement of the underground rocks produces energy waves that moves the Earth’s surface.
These waves are called Seismic Waves. These waves could travel through and on the surface that cause the shaking and vibrations of the ground.
There are 2 types of Seismic waves: Body waves and Surface Waves.
Basically body waves are waves that travel through the Earth’s inner layer. And while Surface waves are waves that can ONLY travel through the surface layer, making the Body waves travel faster than the surface waves. However, surface waves causes more damage than the body waves.
Now there are 2 types of body waves.
The Primary Waves and the Secondary Waves.
Enjoy this video about Seismic Waves.
#SeismicWaves #Physics #EducationalVideo
CONTACT US
Email: [email protected]
Facebook Page: https://www.facebook.com/EarthPen
Youtube Channel: https://www.youtube.com/channel/UCX1Hh7CvEc3RCUd4NRBWJMw
How to learn about the occurrence of an earthquake by analyzing the seismogram recordings of the seismic waves.
Download the Reference Table here: https://bit.ly/3ctUaX1 Additional science videos and resources at: https://science.glide.page
Subscribe to my channel: https://www.youtube.com/user/mikesammartano?sub_confirmation=1
www.iris.edu/earthquake for more animations.
Modern seismometers include 3 elements to determine the simultaneous movement in 3 directions: up-down, north-south,and east-west. Each direction of movement gives information about the earthquake. This animation shows both the movement of the three basic waves (P, S, and surface) and the effect of the waves on a building. The three seismograms produced by a modern seismograph station show that the P wave is more visible on the vertical component and the S wave amplitude is larger on the horizontal components.
We emphasize that seismic waves traveling away from an earthquake occur everywhere, not just at seismic stations.
Reviewed and narrated by Wendy Bohon, Informal education specialist, Incorporated Research Institutions for Seismology.
Animated by Jenda Johnson, Earth Sciences Animated.
Reviewed by Danielle Sumy, Incorporated Research Institutions for Seismology.
Made possible by support from the National Science Foundation.
Music: “On the Passing of Time”, Kevin MacLeod.
How a Seismograph Works
This video is part of a free science course for homeschool students. The labsheets, textbooks, quizzes, and other materials can be accessed 100% free of charge at http://www.HandsomeScienceTeacher.com
Mr. Bertoch covers your entire science curriculum.
Hundreds of articles
Hundreds of videos
Hands-on Labs
All laid out in on a week-by-week easy to follow plan.
Totally Free!
...
Buy us a coffee here: https://bmc.link/caseismograph
Permanent URL: YouTube.com/caseismograph/live
Click here 4 Sales: https://caseismograph.com/
CaSei-G7: https://docs.google.com/spreadsheets/d/1kqkp3EwDfalhEF3rxnLExrSWL3z0CDH1NfuTgxrg5JY/edit?usp=sharing
An explanation of the abbreviations can be found at the bottom of this page.
Please read the description of this feed below. This will greatly help you understand what you are seeing on this YouTube Live site.
Welcome, CaSeismograph is the only featured self-made physical seismograph drum internet live feed in the world! We strive to create a live feed that will serve Southern California people giving everyone a chance to communicate and exchange information about local earthquakes and future events. As you can imagine, this endeavor is quite an undertaking and we thank you for your support as we look forward to daily growing and informing people of earthquake activity in the SOCAL area.
CaSeismograph is for the young and old, and everyone in between. We desire to keep CaSeismograph a child-friendly place and as scientific and accurate in all aspects. This is why our chat is moderated and we expect the chat users to follow the CaSeismograph Team rules. Please be courteous so everyone will undoubtedly have an enjoyable time.
For more in-depth information on our site, please click here:
https://raspberryshake.org/news/southern-california-live-seismic-activity-on-youtube/
All Physical seismographs, earthquake graphics, images, background, content, video, voice content captured in this live feed are the property of CaSeismograph, and are NOT intended for redistribution, copying, or repeating unless otherwise approved in writing by the content creator, CaSeismograph on YouTube.
CaSeismograph owns the RS Seismograph in Escondido (https://raspberryshake.org/) Our Temescal Valley sensor is displayed by one of our CaSeismograph members and can be found at the Community Station View page of the https://raspberryshake.org/ site.
Please subscribe and share with friends and family. For any questions or inquiries, you may contact CaSeismograph at [email protected].
Thank you!
- The CaSeismograph Team.
Abbreviations: GG = Garden Grove
GMS = Ground Motion Sensor
H = Horizontal
N = North
E = East
S = South
W = West
SMS = Surface Motion Sensor
V = Vertical
CNS = Current Needle Sensitivity
CNT = Current Needle Tracking
CDS = Current Drum Speed
SDR = Single Drum Revolution
LS = Line Speed
LW= Line Width
The white X on RS map = location of the drum and e-Graph
Daytime CNS settings should be between 1000-1500. If/when the CNS setting is over 1550, the needle movement can turn the paper black. Most of the daytime needle movement is caused by urban noise. Earthquakes are still visible during high CNS settings because they overpower the smaller needle movement caused by traffic/construction. Examples of earthquake signatures made by our drums / e-Graphs, click here: https://www.youtube.com/c/CaSeismograph/videos
CaSeismograph has proprietary rights to all content displayed on the CaSeismograph live site.
The Raspberryshake map and RS stations are displayed with the full consent of Raspberryshake.
The EQ list is composed of public domain information found at:
https://scedc.caltech.edu/recent/Quakes/quakes0.html and
https://www.emsc-csem.org/Earthquake/world/
There are currently three hand-picked RS stations we believe to have very well-located RS
geophone sensors. We have displayed them as a guest on our site and would like to get in contact with either one of the owners. Please contact us at [email protected] and we would love to speak to you about officially supporting your RS sensor with credit to your name on our channel.
If you are having a life-threatening emergency, please disconnect and dial 911.
Animation of the principles of a drum-style vertical seismograph station that records up-and-down movement. Seismographs are designed so that slight earth vibrations move the instrument. The suspended mass remains at rest as the spring absorbs some of the motion. The stylus (pen) affixed to the mass, records the relative motion between itself and the rest of the instrument, thus recording the ground motion.
More Info at:
http://www.iris.edu/hq/programs/education_and_outreach/aotm/8
What is a Seismic Wave?
What happens if you disturb the water of a calm pond?
Yes exactly!
When you disturb the water, it will continuously produce ripples or waves.
Just like in an earthquake, the sudden movement of the underground rocks produces energy waves that moves the Earth’s surface.
These waves are called Seismic Waves. These waves could travel through and on the surface that cause the shaking and vibrations of the ground.
There are 2 types of Seismic waves: Body waves and Surface Waves.
Basically body waves are waves that travel through the Earth’s inner layer. And while Surface waves are waves that can ONLY travel through the surface layer, making the Body waves travel faster than the surface waves. However, surface waves causes more damage than the body waves.
Now there are 2 types of body waves.
The Primary Waves and the Secondary Waves.
Enjoy this video about Seismic Waves.
#SeismicWaves #Physics #EducationalVideo
CONTACT US
Email: [email protected]
Facebook Page: https://www.facebook.com/EarthPen
Youtube Channel: https://www.youtube.com/channel/UCX1Hh7CvEc3RCUd4NRBWJMw
A seismogram is a graph output by a seismograph. It is a record of the ground motion at a measuring station as a function of time. Seismograms typically record motions in three cartesian axes (x, y, and z), with the z axis perpendicular to the Earth's surface and the x- and y- axes parallel to the surface. The energy measured in a seismogram may result from an earthquake or from some other source, such as an explosion. Seismograms can record lots of things, and record many little waves, called microseisms. These tiny microseisms can be caused by heavy traffic near the seismograph, waves hitting a beach, the wind, and any number of other ordinary things that cause some shaking of the seismograph.
Historically, seismograms were recorded on paper attached to rotating drums. Some used pens on ordinary paper, while others used light beams to expose photosensitive paper. Today, practically all seismograms are recorded digitally to make analysis by computer easier. Some drum seismometers are still found, especially when used for public display. Seismograms are essential for finding the location and magnitude of earthquakes.
I love seismograms. I can’t read music and my foreign language skills are pathetic but one glance at a seismogram and I can make up a credible story of what happened ... “Make Your Own Seismogram” website.