Download the Telopea Park School`s seismometer

Discovery (or rediscovery) the
Telopea Park School’s seismometer - CANB
Sciences building
Google Map
Data Logging Room Station SAGE
GPS antenna
on the roof
Seismometer sensor underground
Caroline Prevot, LFAC, Australia 2012
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You know that an earthquake has just happened...
How could I know if the station CANB has recorded it?
The following links connect to the SAGE device at Telopea Park School:
Station with a computer is a server that can be queried remotely online (public IP station). Enter the
public IP address (if the station is accessible via the Internet)
http://203.62.116.10
> ou http://canb.telopea.act.edu.au
> <http://canb.telopea.act.edu.au/cgi-bin/ida>
Find the coordinates of the station
Network: SE
Station: CANB
Location: Canberra Australia
Station Latitude: -35.31
Station Longitude: 149.13
Station Elevation (m): 580.0
Sensor: NOEMAX
The top link today provides the data being picked up in Canberra, and the history of recordings from
our ‘SAGE’ device.
The second link last days shows the history from Telopea Park School’s device. The horizontal lines
(red and blue) are 30 minute intervals. The bottom line (in grey) shows the 24 hr earthquake record,
and provides a quick way to pick out the big ones, like the 7.0.
Caroline Prevot, LFAC, Australia 2012
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Discover the data...
Learn more about the earthquake of 31/08/2012
The link http://www.edusismo.org/datas_sismo.php allows access to the international network of
schools Sismo.
Choose seismic News, then select the event you are interested, for example the earthquake of
31/08/2012 : http://www.edusismo.org/seisgram1.asp?id=26353
Check if the station CANB has recorded that you need.
Caroline Prevot, LFAC, Australia 2012
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How do I open and read a seismogram?
You must have the following executable (it works in a network)
http://alomax.free.fr/seisgram/SeisGram2K.html and a recent version of JAVA
Then select Z alone (one seismogram) or ZNE (3 components)
Z: vertical component V
N: NS horizontal component
E: EO horizontal component
Seismograms of the earthquake of 31/08/2012 in the Philippine Islands region
Caroline Prevot, LFAC, Australia 2012
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What are the three components of displacement recorded material?
A seismometer is a motion sensor of the soil. It comprises a sensor of movement of the soil, a
transducer which transforms the movements of the ground electrical signals *, an amplifier and a
recorder.
To describe completely the movement of the earth surface, it takes three seismometers (or three
sensors): one vertical and two horizontal (NS and EW), placed in the same transmitter.
The seismometer CANB recorded for the earthquake of 31/08/2012 soil movements in the three space
directions (or Z axis V: vertical axis or E EO: East-West axis NS or N: axis North-South).
These displacements are related to the vibration directions of seismic waves.
The vibrating direction of the P wave is parallel to the propagation direction and the direction of
propagation is not necessarily perpendicular to the surface, it can record a motion associated with the
passage of the P wave on the three axes the mark (see the projection of the vector P on the 3 axes in
the figure below).
Source: ENS de Lyon
Caroline Prevot, LFAC, Australia 2012
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Where do the waves recorded by CANB station come from?
When the earth shook, seismic waves are produced…
Epicentre
Raleigh waves
Surface waves
Fracture, sudden
movement on
fault.
Love waves
Surface waves
P waves
compression
waves
Fault
Reflective wave
Focus
S waves
shear wave
Rock
When you look at a seismogram, these are all the seismic waves that the seismograph has recorded. Most
of these waves were so small that nobody felt them. 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.
There may also be some little dots or marks evenly spaced along the paper. These are marks for every
minute that the drum of the seismograph has been turning.
Caroline Prevot, LFAC, Australia 2012
Page 6
What are the different types of seismic waves?
Seismic waves may travel either along or near the earth's surface (Rayleigh and Love waves) or through the
earth's interior (P and S waves).
HTTP://WWW.GEO.MTU.EDU/UPSEIS/LOCATING.HTML
A P wave or compressional wave is a seismic body wave that shakes the ground back and forth in the same
direction and the opposite direction as the direction the wave is moving. They are responsible for rumble that
can be heard at the beginning of an earthquake. They are first recorded on a seismogram.
An S wave, or shear wave, is a seismic body wave that shakes the ground back and forth perpendicular to the
direction the wave is moving. They are recorded in the second on the seismograms.
A surface wave is a seismic wave that is trapped near the surface of the earth. They are slower than body waves
but the amplitude is generally strong and they concentrate the maximum energy.
A Rayleigh wave is a seismic surface wave causing the ground to shake in an elliptical motion, with no
transverse, or perpendicular, motion
Caroline Prevot, LFAC, Australia 2012
Page 7
The Love wave is propagated only in inhomogeneous solid. It is a polarized shear wave in the horizontal plane.
The displacement is substantially the same as that of S-waves but without vertical movement. Love waves cause
horizontal shaking and cause a lot of damage by shear building foundations. Love waves are faster than Rayleigh
waves.
Source illustrations: USGS
Caroline Prevot, LFAC, Australia 2012
Page 8
How can I learn more about your earthquake?
Collect data from the USGS
http://earthquake.usgs.gov/earthquakes/eventpage/usc000cc5m
Discover the location of the earthquake, its depth, tectonic context...
Discover the history of the region seismic Philippines
• 1976 08 16 - Mindanao, Philippines - M 7.9 Fatalities 8.000
• 16 July 1990 - Luzon, Philippine Islands - M 7.7 Fatalities 1.621
• 2001 01 01 - Mindanao, Philippines - M 7.5
• 2002 03 05 - Mindanao, Philippines - M 7.5 Fatalities 15
• 2003 11 18 - Samar, Philippines - M 6.5 Fatalities 1
• 2004 10 08 - Mindoro, Philippines - M 6.5
• 2009 10 04 - Moro Gulf, Mindanao, Philippines - M 6.6
• 2010 07 23 - Moro Gulf, Mindanao, Philippines - M 7.3
• 2010 07 23 - Moro Gulf, Mindanao, Philippines - M 7.6
• 2010 07 23 - Moro Gulf, Mindanao, Philippines - M 7.4
Caroline Prevot, LFAC, Australia 2012
Page 9
Mapping seismic hazard in the area where there was an earthquake...
The region appears to be in a subduction zone. The location justifies the many powerful earthquakes that occur
there.
And many other discoveries
Have a good “trip”…
Caroline Prevot, LFAC, Australia 2012
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