1. SUPERSITES COORDINATION WORKSHOP Monday 10 June 2013
Stable levelling and locking methods applicable for borehole very broad band
seismic sensors including tilt meters
presented at
SUPERSITES COORDINATION WORKSHOP Monday 10 June 2013
Cansun Guralp

2. Why borehole instruments?
Reduce the seismic back ground noise
Facilitates to record seismic data under reduced noise conditions in the long period and short period seismic bands thereby improving:
signal‐to‐noise ratio
magnitude detection threshold
precision of hypocentre determination
Get closer to the source of earthquakes
Allows to broaden the frequency band of the recorded seismic signals including high frequency components.
Provide multidisciplinary seismic observatory
Strong motion
Broad band 360 second period to 200 Hz, with single jaw hole lock.
Two axis tilt meter with three jaw hole-lock
High resolution Temperature sensor
Strain gauge, cemented

3. CMG-3TB Seismometer Deployment options for installation:
with a hole-lock
Single arm hole lock with skids
Three jaw hole lock
or with bishops hat orientation system
in SAND packed borehole, without a hole lock
Cemented sensor
in a cased borehole
in an un-cased borehole
Other features:
Options such as Horizontal component orientation
provided with integrated accelerometer
The CMG-3 is a true low noise, high dynamic range broadband seismometer. CMG-3T sensor designed and first produced in 1987 has become a standard with over 3,300 sensors in use World Wide.
Sensors can be provided in borehole configurations as either a three component or a vertical component sensor or as a triaxial vault Sensor. The CMG-3TB sensors have been a mainstream product since 1991 when the sensors were installed as part of the USGS NSN program. The sensor design is modular and flexible in concept. Modules consist of Vertical, North/South and East West components ad an optional holelock assembly. Modules are completely interchangeable. Extensive development has been carried out on the product since its original conception. The latest sensors are built under a stringent ISO9001:2008 accredited quality procedure. Detailed design and repair review has lead to significant enhancements of the Motors, centring drive shafts, Magnet keepers, Feedback coils, Connectors, Printed circuit boards, wiring, and electronic components used in the Sensor. Sensors have been tested under extreme environmental conditions (vibration and temperature)
The CMG-3T has been designed and manufactured as a commercial sensor. The following details are provided in commercial confidence in order to give insight and confidence in the durability and low cost of ownership for the sensors. Failure rates are extremely low for the CMG-3TB, warranty repair % are less than 1% and the product has a demonstrated MTBF in excess of 10 years (excluding act of God and mishandling events).

4. CMG-3TB: example of some Global Installations
Bangladesh
Pakistan
Kazakhstan
Taiwan
China
Russia
Japan
South Korea
Australia
New Zealand
Turkmenistan
Oman
Saudi Arabia
Turkey
Iran
Israel
Niger
Switzerland
Belgium UK
Norway
Senegal
Tunisia
Montserrat
Brazil
Peru
Mexico
USA
Antarctica

5. CMG-3TB Seismometer With three jaw hole-lock
The CMG-3 is a true low noise, high dynamic range broadband seismometer. CMG-3T sensor designed and first produced in 1987 has become a standard with over 3,300 sensors in use World Wide.
Sensors can be provided in borehole configurations as either a three component or a vertical component sensor or as a triaxial vault Sensor. The CMG-3TB sensors have been a mainstream product since 1991 when the sensors were installed as part of the USGS NSN program. The sensor design is modular and flexible in concept. Modules consist of Vertical, North/South and East West components ad an optional holelock assembly. Modules are completely interchangeable. Extensive development has been carried out on the product since its original conception. The latest sensors are built under a stringent ISO9001:2008 accredited quality procedure. Detailed design and repair review has lead to significant enhancements of the Motors, centring drive shafts, Magnet keepers, Feedback coils, Connectors, Printed circuit boards, wiring, and electronic components used in the Sensor. Sensors have been tested under extreme environmental conditions (vibration and temperature)
The CMG-3T has been designed and manufactured as a commercial sensor. The following details are provided in commercial confidence in order to give insight and confidence in the durability and low cost of ownership for the sensors. Failure rates are extremely low for the CMG-3TB, warranty repair % are less than 1% and the product has a demonstrated MTBF in excess of 10 years (excluding act of God and mishandling events).

6. Borehole Sensor with three jaw hole lock
Some examples of borehole seismometer packages 6 6 6

7. Borehole Sensor with three jaw hole lock
Some examples of borehole seismometer packages 7 7 7

8. Joint experiment: 3T/5T borehole sensor + DM24 at >1000 m depth,
Closer to source I
Joint experiment:
3T/5T borehole
sensor + DM24 at
>1000 m depth,
optical data
transmission
to well head

9. Closer to source II
Our sensor deployed at
m in Pilot Hole

11. Example of typical down-hole recording: Microearthquakes not observed on surface, most common type of microearthquake observed: S-P time: 0.74 sec hypocentral distance between 4-5 km

12. Earth Tides

13. some peculiarities to be resolved:
1. ultra long period (4-8 min) noise
Pinnacle tiltmeter (2007)

14. CMG-3TB Case Studies
Data from 4 different sensor installations at the same location, high frequency performance of 3TB is clearly demonstrated
Presented at the IRIS Broad-Band Instrumentation Workshop; Lake Tahoe, Mar 24-26, 2004 14 14 14

15. CMG-3TBD Seismometer
Titanium case with three component broad band sensor 360 sec to 50 Hz.
± 5 degrees of tilt compensation.
4 Channel 24 bit digitiser with time synchronisation.
Mass position outputs used as tilt data and compared to a very high resolution tilt sensor 5*10-9 radian.
Deployed with cement at 3000 meter depth meters sea water and 600 meters of sea bottom borehole.
The CMG-3 is a true low noise, high dynamic range broadband seismometer. CMG-3T sensor designed and first produced in 1987 has become a standard with over 3,300 sensors in use World Wide.
Sensors can be provided in borehole configurations as either a three component or a vertical component sensor or as a triaxial vault Sensor. The CMG-3TB sensors have been a mainstream product since 1991 when the sensors were installed as part of the USGS NSN program. The sensor design is modular and flexible in concept. Modules consist of Vertical, North/South and East West components ad an optional holelock assembly. Modules are completely interchangeable. Extensive development has been carried out on the product since its original conception. The latest sensors are built under a stringent ISO9001:2008 accredited quality procedure. Detailed design and repair review has lead to significant enhancements of the Motors, centring drive shafts, Magnet keepers, Feedback coils, Connectors, Printed circuit boards, wiring, and electronic components used in the Sensor. Sensors have been tested under extreme environmental conditions (vibration and temperature)
The CMG-3T has been designed and manufactured as a commercial sensor. The following details are provided in commercial confidence in order to give insight and confidence in the durability and low cost of ownership for the sensors. Failure rates are extremely low for the CMG-3TB, warranty repair % are less than 1% and the product has a demonstrated MTBF in excess of 10 years (excluding act of God and mishandling events).

16. CMG-3TB Seismometer
The CMG-3 is a true low noise, high dynamic range broadband seismometer. CMG-3T sensor designed and first produced in 1987 has become a standard with over 3,300 sensors in use World Wide.
Sensors can be provided in borehole configurations as either a three component or a vertical component sensor or as a triaxial vault Sensor. The CMG-3TB sensors have been a mainstream product since 1991 when the sensors were installed as part of the USGS NSN program. The sensor design is modular and flexible in concept. Modules consist of Vertical, North/South and East West components ad an optional holelock assembly. Modules are completely interchangeable. Extensive development has been carried out on the product since its original conception. The latest sensors are built under a stringent ISO9001:2008 accredited quality procedure. Detailed design and repair review has lead to significant enhancements of the Motors, centring drive shafts, Magnet keepers, Feedback coils, Connectors, Printed circuit boards, wiring, and electronic components used in the Sensor. Sensors have been tested under extreme environmental conditions (vibration and temperature)
The CMG-3T has been designed and manufactured as a commercial sensor. The following details are provided in commercial confidence in order to give insight and confidence in the durability and low cost of ownership for the sensors. Failure rates are extremely low for the CMG-3TB, warranty repair % are less than 1% and the product has a demonstrated MTBF in excess of 10 years (excluding act of God and mishandling events).

17. The CMG-3 is a true low noise, high dynamic range broadband seismometer. CMG-3T sensor designed and first produced in 1987 has become a standard with over 3,300 sensors in use World Wide.
Sensors can be provided in borehole configurations as either a three component or a vertical component sensor or as a triaxial vault Sensor. The CMG-3TB sensors have been a mainstream product since 1991 when the sensors were installed as part of the USGS NSN program. The sensor design is modular and flexible in concept. Modules consist of Vertical, North/South and East West components ad an optional holelock assembly. Modules are completely interchangeable. Extensive development has been carried out on the product since its original conception. The latest sensors are built under a stringent ISO9001:2008 accredited quality procedure. Detailed design and repair review has lead to significant enhancements of the Motors, centring drive shafts, Magnet keepers, Feedback coils, Connectors, Printed circuit boards, wiring, and electronic components used in the Sensor. Sensors have been tested under extreme environmental conditions (vibration and temperature)
The CMG-3T has been designed and manufactured as a commercial sensor. The following details are provided in commercial confidence in order to give insight and confidence in the durability and low cost of ownership for the sensors. Failure rates are extremely low for the CMG-3TB, warranty repair % are less than 1% and the product has a demonstrated MTBF in excess of 10 years (excluding act of God and mishandling events).

18. The CMG-3 is a true low noise, high dynamic range broadband seismometer. CMG-3T sensor designed and first produced in 1987 has become a standard with over 3,300 sensors in use World Wide.
Sensors can be provided in borehole configurations as either a three component or a vertical component sensor or as a triaxial vault Sensor. The CMG-3TB sensors have been a mainstream product since 1991 when the sensors were installed as part of the USGS NSN program. The sensor design is modular and flexible in concept. Modules consist of Vertical, North/South and East West components ad an optional holelock assembly. Modules are completely interchangeable. Extensive development has been carried out on the product since its original conception. The latest sensors are built under a stringent ISO9001:2008 accredited quality procedure. Detailed design and repair review has lead to significant enhancements of the Motors, centring drive shafts, Magnet keepers, Feedback coils, Connectors, Printed circuit boards, wiring, and electronic components used in the Sensor. Sensors have been tested under extreme environmental conditions (vibration and temperature)
The CMG-3T has been designed and manufactured as a commercial sensor. The following details are provided in commercial confidence in order to give insight and confidence in the durability and low cost of ownership for the sensors. Failure rates are extremely low for the CMG-3TB, warranty repair % are less than 1% and the product has a demonstrated MTBF in excess of 10 years (excluding act of God and mishandling events).

20. The CMG-3TB can be installed in SAND, or holes using the single Jaw holelock. The single jaw holelock can optionally have a cable pass through to allow multiple units to be installed in a single hole. In addition the unit can be supplied with a bishops hat orientation system to physically align the borehole system in the NS direction (not shown here)
A downhole digitiser can be provided. This can have RS-422 or fibre optic output to the surface. The downhole 24-bit digitiser acts as (and replaces) the strain relief mechanism.

21. Reduce the seismic noise
Facilitates to record seismic data under reduced noise conditions in the long period and short period seismic bands thereby improving:
signal‐to‐noise ratio
magnitude detection threshold
precision of hypocentre determination
Get closer to the source of earthquakes
Allows to broaden the frequency band of the recorded seismic signals including high frequency components.
Provide multidisciplinary seismic station
Strong motion
Broad band 360 second period to 200 Hz, with single jaw hole lock.
Two axis tilt meter with three jaw hole-lock
Hydrophone
High resolution Temperature sensor
Strain gauge, cemented

22. Thank You !

23. CMG-3TB Case Studies Matsushiro, Japan. Installed April 2008
Deployed at a depth of 700m
CMG-3TB very broadband (VBB) velocity sensor with response from 360s to 100Hz;
CMG-5TB strong motion sensor with response from DC to 200Hz;
CMG-DM24mk3 7-channel 24-bit downhole digitiser with serial to optical converter;
Single jaw hole lock (pressure compensated). 23 23 23

24. Above a Magnitude 6.4 in Crete recorded on all four sensors
CMG-3TB Case Studies (Belgium)
Above a Magnitude 6.4 in Crete recorded on all four sensors 24 24 24

25. CMG-3TB Case Studies Nuclear Explosion Treaty Monitoring
In excess of 50 CMG-3TB's are used world wide in motioning networks, in addition over 100 single component vertical CMG-3V sensors are used for short period elements due to their unrivalled slow self noise and high linearity. 25 25 25

26. CMG-3TB Case Studies
The above sensors feature a bishop hat orientation module allowing them to use the original KS and KS holelock mechanisms retaining the same physical orientation in the Boreholes 26 26 26