SLIDE 1
WP 4. Establishment of Borehole Observation System and High Resolution Seismic Studies in the Marmara Sea
Oğuz Özel ( I.U ; KOERI ; GFZ ; CNRS ; TUBITAK ; GURALP )
SLIDE 2 WP 4. Establishment of Borehole Observation System and High
Resolution Seismic Studies in the Marmara Sea
- Quite different contents of seismograms recorded by borehole and surface
instruments because of the near-surface geology effects that mask the source related information,
- Better monitoring of rupture nucleation process of earthquakes. Deploying
a borehole system may yield invaluable data to closely inspect and monitor the last stages of the rupture
- Opportunity to study source parameters and to determine input ground
motion by using borehole recordings having high S/N ratio
- Recent advances in seismic noise correlation techniques
- Promising results on repeating earthquakes to be a powerful tool to
investigate how tectonic plates move relative to one another
- Close connection between slow slip and the nucleation of large earthquakes
Motivation:
SLIDE 3 WP 4. Establishment of Borehole Observation System and High
Resolution Seismic Studies in the Marmara Sea
The objectives;
- To design and install a multi-parameter borehole system and surface array, as
closest as to the main Marmara Fault (MMF) in the western Marmara Sea, and to monitor the seismic activity in the western part of MMF,
- To monitor continuously the evolution of the state of stress of the fault zone
surrounding the MMF, and to detect any anomaly or change which may occur before earthquakes by making use of high resolution data from the arrays already running in the eastern part of the Marmara Sea (PIRES and CINNET), and the data from the new borehole system and surface array in the western part of
- MMF. The data from KOERI, TUBITAK and ARNET will also be integrated to the
data set to be used in the analysis.
SLIDE 4
The seismicity of the Marmara Region (1964-2011, M≥2.5).
PIRES CINNET ARNET
WP 4. Establishment of Borehole Observation System and High
Resolution Seismic Studies in the Marmara Sea
SLIDE 5
Deployment of surface microearthquake array and borehole seismometers and integrating of borehole and surface array data for better location of microearthquakes
- O. Ozel – ( IU, GURALP Systems (SME), GFZ)
- TASK-2.
Analyzing response of near-surface geology to earthquake ground motion and its effects masking the source related information through borehole data
- S. Parolai – (GFZ, IU)
- TASK-3.
Monitoring the fault zone and source process in the near field
- M. Bouchon – (CNRS, KOERI, IU)
- TASK-4.
High Resolution Seismology in Marmara Sea with Arrays
- M. Aktar – (KOERI, GFZ, CNRS)
- TASK-5.
Monitoring structural characteristics on Çınarcık Fault (CINNET)
- H. Karabulut – (KOERI, CNRS)
WP 4. Establishment of Borehole Observation System and High
Resolution Seismic Studies in the Marmara Sea
SLIDE 6 TASK-1 Deployment of surface microearthquake array and borehole seismometers and integrating of borehole and surface array data for better location of microearthquakes Objectives:
- To design and build multiparameter borehole system consisting of very wide dynamic
range and stable borehole (VBB) broad band seismic sensor, and incorporate 3-D strain meter, tilt meter, and temperature and local hydrostatic pressure measuring devices,
- Determination of 1-D S-wave velocity structure beneath the borehole system by array
analysis,
- To design and install surface array, and to combine the data from this array with
borehole data, which will provide high SNR, lower threshold level and earthquake location improvement,
- To precisely monitor the microseismic activity in the western part of the Marmara Sea.
WP 4. Establishment of Borehole Observation System and High
Resolution Seismic Studies in the Marmara Sea
SLIDE 7 SBT4 SBT3
WP 4. Establishment of Borehole Observation System and High
Resolution Seismic Studies in the Marmara Sea
SLIDE 8
WP 4. Establishment of Borehole Observation System and High
Resolution Seismic Studies in the Marmara Sea
SLIDE 9 TASK-2. (Task Leader: Stefano Parolai) Analyzing response of near-surface geology to earthquake ground motion and its effects masking the source related information through borehole data Objectives:
- Determination of surface and near-surface effects on seismic waves,
- Estimation of the near-surface geology effects masking the source related
information
- To test, improve and develop different methods for correcting the borehole
seismograms, (correction due to contamination of down-going waves and site effects; Parolai et al., 2009)
WP 4. Establishment of Borehole Observation System and High
Resolution Seismic Studies in the Marmara Sea
SLIDE 10 TASK-3. (Task Leader: Michel Bouchon) Monitoring the fault zone and source process in the near field Objectives:
- Monitoring rupture nucleation and propagation using borehole and surface
array data,
- Closely inspection and monitoring of the last stages of the preparation stage
- f a major rupture,
- To measure continuously the evolution of the state of stress of the fault
zone surrounding the MMF, and to detect any anomaly or change , which may
- ccur before earthquakes,
- To identify the presence of repeating earthquakes along the MMF.
WP 4. Establishment of Borehole Observation System and High
Resolution Seismic Studies in the Marmara Sea
SLIDE 11 Record of the vertical ground motion 20 min before the earthquake. This recording is part
- f the second triggered window. The numbers indicate the foreshocks and refer to their
chronological order from the start of the sequence. (Bouchon et al., 2011)
WP 4. Establishment of Borehole Observation System and High
Resolution Seismic Studies in the Marmara Sea
SLIDE 12 TASK-4. (Task Leader: Mustafa Aktar) High Resolution Seismology in Marmara Sea with Arrays Objectives:
- To better understand the existing seismically active structures and
their role in local tectonic settings,
- To understand the stress transfer mechanism from east to west,
- To study the structural properties of the fault zone,
WP 4. Establishment of Borehole Observation System and High
Resolution Seismic Studies in the Marmara Sea
SLIDE 13
The PIRES network: Monitoring microseismicity at the Princes Islands segment of the North Anatolian Fault Zone
WP 4. Establishment of Borehole Observation System and High
Resolution Seismic Studies in the Marmara Sea
SLIDE 14 Earthquake 3 July 2008 , 06:08.32
Distance = 10 km back-azimuth estimation from 10 km : ~ 30 error
Earthquake 3 July 2008 , 06:08.32
WP 4. Establishment of Borehole Observation System and High
Resolution Seismic Studies in the Marmara Sea
SLIDE 15 TASK-5. Monitoring structural characteristics on Çinarcik Fault (CINNET) Objectives:
- To obtain continuous high resolution locations of micro-seismicity including
development of relative location technique from cross-correlation methods (multiplet analysis) and study the space-time evolution of the activity,
- To search for low frequency events (non-volcanic tremor) from continuous
recording,
- To analyze triggering mechanisms like Coulomb transfer, aseismic slip, or
fluid migration and possible declustering methods.
WP 4. Establishment of Borehole Observation System and High
Resolution Seismic Studies in the Marmara Sea
SLIDE 16
Station Distribution Networks : KOERI-NEIC, AFAD, Cinnet (Koeri-CNRS)
WP 4. Establishment of Borehole Observation System and High
Resolution Seismic Studies in the Marmara Sea
CINNET Stations KOERI Stations AFAD Stations
SLIDE 17
Seismicity 2000–2011
The thickness of the seimogenic zone is increasing to the west
WP 4. Establishment of Borehole Observation System and High
Resolution Seismic Studies in the Marmara Sea
SLIDE 18
DATA ACQUISITION and SHARING TUBITAK Stations KVKM SART SGTM YNKM KOERI Stations SBT4 SBT3 MRMT CRLT RKY (Event Base) Borehole System & Surface Array Task-1 WP-4 Task- 2 WP-4 Task- 5 WP-4 Task- 3 WP-4 Task- 4 Main Server For WP-4 Sub-Server Data Integration and Dissemination WP-10
WP- 2 WP- 3 WP- 6
WP 4. Establishment of Borehole Observation System and High
Resolution Seismic Studies in the Marmara Sea
SLIDE 19 WP 4. Establishment of Borehole Observation System and High
Resolution Seismic Studies in the Marmara Sea TASK-1 TASK-2 TASK-3 TASK-4 TASK-5 Data Integration and Dissemination WP-10
D4.1. Surface Microearthquake Array and Borehole System Implementation D4.2. Report on the Analysis of the Response of the Near Surface Geology on Earthquake Ground Motion D4.3. Report on the High-Resolution Monitoring in the Sea of Marmara using Land-Based Arrays D4.4. Report on the High-Resolution Monitoring and Analysis of the Seismicity and Velocity Perturbations D4.5. Report on Detection and Cross-Correlation
- f Quarry Blasts and Receiver Function
D4.6. Report on Statistical Analysis and Modeling
- f Seismic Cluster Triggering Mechanisms
SLIDE 20
Thank You
