COMPILATION OF STRONG MOTION DATA FROM EASTERN CANADA FOR NGA-EAST PROJECT Lan Lin Postdoctoral Fellow, Geological Survey of Canada

Motivation Ground motion data are very important for seismologists and earthquake engineers. Ground motion data are very important for seismologists and earthquake engineers. Processed data are useful for the development of attenuation relations for eastern North America. Processed data are useful for the development of attenuation relations for eastern North America. Strong motion data from eastern Canada have not been complied and processed. Strong motion data from eastern Canada have not been complied and processed.

Strong Motion Monitoring In Eastern Canada Started in 1970s (AR-240 instruments). Started in 1970s (AR-240 instruments). First record: 1979 Charlevoix m N 5.0 earthquake. First record: 1979 Charlevoix m N 5.0 earthquake. Analog (SMA-1) Network deployed in 1970s to record “next” Charlevoix earthquake on rock sites. Analog (SMA-1) Network deployed in 1970s to record “next” Charlevoix earthquake on rock sites. -- recorded Saguenay mainshock, Quebec -- recorded Saguenay mainshock, Quebec /11/ /11/25 -- magnitude m N =6.5, distance from 43 to 200 km -- magnitude m N =6.5, distance from 43 to 200 km

Strong Motion Monitoring In Eastern Canada Analog (SMA-1) instruments deployed during aftershock sequences: Analog (SMA-1) instruments deployed during aftershock sequences: -- Miramichi, New Brunswick, 1982, magnitude m N = Miramichi, New Brunswick, 1982, magnitude m N = Nahanni, Northwest Territories, 1985, magnitude m N = Nahanni, Northwest Territories, 1985, magnitude m N = SMA records from Saguenay Eq, 33 SMA records from Saguenay Eq, 14 from Miramichi Eq, 16 from Nahanni Eq. 14 from Miramichi Eq, 16 from Nahanni Eq.

SMA-1 instruments replaced by ETNA (on-site digital recording) ( ). SMA-1 instruments replaced by ETNA (on-site digital recording) ( ). ETNAs supplemented by Internet Accelerometers (IA) 2004 onwards. ETNAs supplemented by Internet Accelerometers (IA) 2004 onwards. ETNA InstrumentIA Instrument Strong Motion Monitoring In Eastern Canada

Eastern Canadian Strong-Motion Network (does not include IA instruments or instruments operated by Hydro-Quebec, etc) GSC ETNA Stations Quebec Ontario New Brunswick Charlevoix Region Ottawa

ETNA Station Information Total 33 stations. Total 33 stations. 13 on free field 13 on free field 20 in basement of 1-2 storey buildings. 20 in basement of 1-2 storey buildings. 26 on bedrock, 7 on soft soil. 26 on bedrock, 7 on soft soil.

ETNA Station Information Registered station code

Characteristics of ETNA Data type: acceleration Data type: acceleration Number of components recorded: two orthogonal horizontal, one vertical Number of components recorded: two orthogonal horizontal, one vertical Sampling rate: 200s/s (i.e., ΔT=0.005s) Sampling rate: 200s/s (i.e., ΔT=0.005s) 10 seconds of pre-event duration 10 seconds of pre-event duration Unit: Volt Unit: Volt

Selected ETNA Records for Canadian Archive Number of records selected: 76 Number of records selected: 76 Number of components: 228 (=76*3) Number of components: 228 (=76*3) Maximum PGA: 0.2g Maximum PGA: 0.2g Maximum magnitude: 5.4 (2005/03/06) Maximum magnitude: m N 5.4 (2005/03/06)

Typical Record Information Magnitude is currently m N - will be changed to moment magnitude

Storage of ETNA Data Canadian National Waveform Archive Canadian National Waveform Archive i.e., accessible to all through web-based tools Data type: raw data, without baseline Data type: raw data, without baseline correction and filtering correction and filtering Data format: CA Data format: CA Data unit: nVolt (=10 9 *Volt) Data unit: nVolt (=10 9 *Volt) Channel code: HNN (N-S) Channel code: HNN (N-S) HNZ (Vertical) HNZ (Vertical) HNE (E-W) HNE (E-W) “SEED” Convention Orientation code Instrument code Band code

Storage Procedure Step 1: Extract original event file (.EVT) for every record. Step 1: Extract original event file (.EVT) for every record. Step 2: Convert.EVT file into ASCII file, Step 2: Convert.EVT file into ASCII file, generate 3 data files, for N-S, V, and E-W comp. generate 3 data files, for N-S, V, and E-W comp. Step 3: Modify ASCII file. Step 3: Modify ASCII file. (a) add header information, i.e., station code, channel code, (a) add header information, i.e., station code, channel code, event start time, sample rate, and number of data points. event start time, sample rate, and number of data points. (b) change units (Volt  nVolt, i.e., multiply by 10 9 ). (b) change units (Volt  nVolt, i.e., multiply by 10 9 ). Step 4: Generate CA file. Step 4: Generate CA file.

Storage Test Event considered: Riviere-du-Loup Eq. 2005/03/06, m N =5.4 Event considered: Riviere-du-Loup Eq. 2005/03/06, m N =5.4 Station: A11 Station: A11 Component: N-S Component: N-S Software for analysis: SAC Software for analysis: SAC

Acceleration (nVolt) Time (s) N-S waveform recorded at station A11 from 2005/03/06 earthquake

Weak-Motion Monitoring Instruments Seismometers Seismometers Data type: VELOCITY Data type: VELOCITY Number of components recorded: two horizontal components, one vertical component Number of components recorded: two horizontal components, one vertical component Sampling rate: 40s/s, 100s/s Sampling rate: 40s/s, 100s/s Unit: Count Unit: Count

Waveforms Similarity Analysis (ETNA vs. Seismometer Records) Waveforms Similarity Analysis (ETNA vs. Seismometer Records) Extract data from weak-motion database Extract data from weak-motion database Same event: 2005/03/06 Same event: 2005/03/06 Same station: A11 Same station: A11 Same component: N-S Same component: N-S

N-S waveform recorded at station A11 for 2005/03/06 earthquake (weak-motion instrument) Velocity (Count) Time (s) Velocity waveform

Time (s) Acceleration (Count/s) Acceleration waveform

Time (s) Acceleration (Count/s) Acceleration (nVolt) Time-lag (s) strong motion waveform by ETNA weak motion waveform by seismometer

Cross-correlation Functions CCF Time-lag=52.25s Time-lag, n (s)

Correlation coefficient=0.993 Time-traces for segment 10s  15s GOOD AGREEMENT!!!

small difference for 1 to 20 Hz. 10% difference for frequency higher than 20 Hz, and lower than 1.0 Hz. Comparison of FFT Spectra Fourier Spectra Ratio of FFT (strong-motion over weak-motion) 20.00Hz +10% -10%

Conclusions Meta-data for records have been assembled. About 300 records for storage. Meta-data for records have been assembled. About 300 records for storage. Waveform storage procedure for ETNA Waveform storage procedure for ETNA data is established. Similar procedure can be used for SMA data and IA data. data is established. Similar procedure can be used for SMA data and IA data. Data from eastern Canada are ready for uploading to Canadian National Waveform Archive. Data from eastern Canada are ready for uploading to Canadian National Waveform Archive.

Future Work Compilation of GSC IA data. Compilation of GSC IA data. Compilation of digitized SMA-1 data from Saguenay, Miramichi and Nahanni Eqs. Compilation of digitized SMA-1 data from Saguenay, Miramichi and Nahanni Eqs. Assembly of strong motion data from other operators, e.g., Hydro-Quebec, if allowed. Assembly of strong motion data from other operators, e.g., Hydro-Quebec, if allowed. Compilation of analog data – how to make available. Compilation of analog data – how to make available.

Thank you!

Characteristics of IA Data type: acceleration Data type: acceleration Number of components recorded: two orthogonal horizontal, one vertical Number of components recorded: two orthogonal horizontal, one vertical Sampling rate: 100s/s (i.e., ΔT=0.01s) Sampling rate: 100s/s (i.e., ΔT=0.01s) Internet-connected (real-time) Internet-connected (real-time) 2 days continuous data plus triggers recorded on internal flash card 2 days continuous data plus triggers recorded on internal flash card NTP clock, drifts ~0.01 sec NTP clock, drifts ~0.01 sec Price about $2500 Price about $2500 GSC design, now available from GSC design, now available fromGeosig.com