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

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

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).

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

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).

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

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

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

Closer to source II Our sensor deployed at 1039.50 m in Pilot Hole

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

Earth Tides

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

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

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. 2400 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).

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).

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).

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).

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.

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

Thank You !

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

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

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

CMG-3TB Case Studies The above sensors feature a bishop hat orientation module allowing them to use the original KS-54000 and KS-36000 holelock mechanisms retaining the same physical orientation in the Boreholes 26 26 26