Reports of Tremor Activity Monitoring System (TAMS)

To better recognize the occurrence of an ETS event during its early stage, the Geological Survey of Canada (GSC) establishes the Tremor Activity Monitoring System (TAMS) in northern Cascadia. TAMS consists of three major modules. The Waveform Retrieval Module works with GSC's real-time seismic acquisition system to fetch required waveforms. The Waveform Analysis Module performs data processing, key-parameter calculations, tremor pattern recognition, and quantitative evaluation of the activity level for a set of predefined sub-regions. The Information Delivery Module handles the post-analysis tasks, including archiving results, preparing summary reports in both text and graphic formats, and delivering them to network operators and researchers. When a high level of tremor activity is detected, an alert message is sent to a pre-compiled list of clients consisting of GSC management and scientific teams, federal and provincial emergency agencies, research institutions in the region, and individuals who asked to be included. For more details about TAMS, please refer to the following papers:

Kao, H., P.J. Thomson, G. Rogers, H. Dragert, and G. Spence (2007), Automatic detection and characterization of seismic tremors in northern Canscadia, Geophys. Res. lett., 34, L16313, doi:10.1029/2007GL030822.

Kao, H., P.J. Thompson, S.-J. Shan, G. Rogers, H. Dragert, and G. Spence (2008), Tremor activity monitoring in northern Cascadia. EOS Trans., AGU, 89(42), 405-406.

For those who wishes to be included in the TAMS email list can send a request email to pgc_info@pgc.nrcan.gc.ca with a statement indicating his/her preference in either the "daily" or the "alert-only" group.

TAMS Daily Summaries for Vancouver Island

One of the main products of TAMS is a chart which plots the daily percentage of coherent tremor station-hours since the year of 1997, and it is displayed below. A coherent tremor station-hour is referred to a given station whose seismic waveforms exhibit coherent tremor patterns for a given hour. The percentage is defined as this Coherent Tremor (CT) station-hours against the total station-hours in a particular region (Southern, Middle or Northern Vancouver Island).

Skip to the text alternative below for the TAMS daily summaries for Vancouver Island

Graph of TAMS Activities from year 1997 and 2012 in Northern, Middle and Southern Vancouver Island. Full description and tables of data found below.

The chart is a composite plot to summarize the TAMS reports from 1997 to 2012 for Northern (top panel), Middle (middle panel) and Southern (bottom panel) Vancouver Island. In each panel the daily percentage of station-hours showing the coherent tremor (CT) pattern is marked by a thick red line plotted at the top, whereas the number of seismic stations available for TAMS analysis is shown by a blue line plotted in the middle. The horizontal axis at the bottom of this chart shows the number of days in each year since year 1997. Clicking the chart will bring a big magnified graph.

The number of seismic stations (plotted with the blue lines) used in the calculation ranges from 3 to 11 in the Northern Vancouver Island, from 4 to 15 in the Middle Vancouver Island, and from 5 to 34 in the Southern Vancouver Island. The daily percentage of station-hours (plotted with the red lines) showing the coherent tremor (CT) pattern varies, and peaks periodically. Comparative studies have shown that the periodic peaks in these charts match very well with the occurrences of major ETS events in Vancouver Island (VI). Recurrence interval of major ETS events in southern VI is remarkably regular at 14 months, whereas the interval in the north is significantly shorter (about 9 months). Since there is a big difference in the plate age and convergence rate between the north and south, our observation seems to suggest that ETS recurrences may be related to tectonic parameters.

TAMS Daily Summaries in Table Format

The table below provides the same information as in the above chart with the exception that the data are broken into one-year intervals. By selecting a different year, that year's data will be displayed accordingly.

TAMS Activities Summary table for Year 2012
DateNorthern Vancouver IslandMiddle Vancouver IslandSouthern Vancouver Island
Percentage of Coherent tremorNumber of StationsPercentage of Coherent tremorNumber of StationsPercentage of Coherent tremorNumber of Stations
2012-01-013.795.691.511
2012-01-027.490110.811
2012-01-031.99011010
2012-01-040.99011010
2012-01-05090.811311
2012-01-061.990.992.311
2012-01-074.691.990.811
2012-01-080.991.99011
2012-01-09080111.511
2012-01-10180.8114.511
2012-01-112.181.5114.212
2012-01-1212.588.3118.312
2012-01-132.184.5114.912
2012-01-145.283.81110.412
2012-01-152.183.8114.511
2012-01-16080113.512
2012-01-17182.3110.712
2012-01-18080.8114.212
2012-01-19090.8111.511
2012-01-202.890112.311
2012-01-21090102.311
2012-01-224.2809011
2012-01-231.990.99010
2012-01-244.690.99510
2012-01-252.890.992.311
2012-01-261.99091.710
2012-01-271.99095.612
2012-01-286.594.697.611
2012-01-291.992.890.810
2012-01-300.991.990.811
2012-01-311.9909011
2012-02-01092.893.811
2012-02-023.790.8114.212
2012-02-030.990.8112.112
2012-02-0412914.41128.512
2012-02-059.394.5116.212
2012-02-068.394.51110.412
2012-02-075.697.6111612
2012-02-081292.3113.512
2012-02-0913.580.8111.412
2012-02-101.990111.412
2012-02-111.99011012
2012-02-122.890114.912
2012-02-130.9901110.412
2012-02-147.4910.6117.612
2012-02-150.995.3112.112
2012-02-167.497.6117.612
2012-02-173.792.3111.412
2012-02-18091.99012
2012-02-190.991.99011
2012-02-204.690.990.712
2012-02-21090.8106.111
2012-02-2209010011
2012-02-23090101.46
2012-02-242.890.8102.47
2012-02-2509096.96
2012-02-26092.893.67
2012-02-275.6912.5105.612
2012-02-280.990101.412
2012-02-2909090.712
2012-03-012.182.5107.113
2012-03-022.47093.813
2012-03-03071.7108.313
2012-03-045.664.871.913
2012-03-051.991.996.413
2012-03-06092.893.813
2012-03-070715.21114.113
2012-03-08074.511913
2012-03-094.695.3115.813
2012-03-1009010013
2012-03-113.6709012
2012-03-121.27095.612
2012-03-1308090.712
2012-03-14075.6913.611
2012-03-1507010011
2012-03-1607010311
2012-03-17060110.811
2012-03-18053.8114.912
2012-03-19063.8112.112
2012-03-20040100.613
2012-03-2106010012
2012-03-22040100.613
2012-03-23041.5111.412
2012-03-242.862.1123.213
2012-03-254.243.5126.413
2012-03-264.262.8127.113
2012-03-275.660121.913
2012-03-28060112.613
2012-03-294.280.8102.112
2012-03-300.990101.511
2012-03-31090.8102.812
2012-04-01093113.512
2012-04-025.280.8111.412
2012-04-0311.190102.112
2012-04-043.790113.512
2012-04-05092.3114.513
2012-04-060.992.8125.113
2012-04-071.272.8125.113
2012-04-083.671.4121.913
2012-04-09080.7121.313
2012-04-100.994.91220.513
2012-04-115.6913.91248.713
2012-04-124.696.91212.213
2012-04-137.493.51210.913
2012-04-14090122.613
2012-04-152.890.712013
2012-04-162.890.7129.613
2012-04-173.790.7121.313
2012-04-1811.161.412013
2012-04-195.661.4121.313
2012-04-20060120.613
2012-04-21060.7122.613
2012-04-226.960.7125.813
2012-04-23061.4126.413
2012-04-2411.162.8124.513
2012-04-258.366.2125.813
2012-04-268.361.4123.213
2012-04-2716.766.2128.313
2012-04-2823.664.91210.313
2012-04-298.361.412013
2012-04-3015.363.5124.513
2012-05-010.993.5123.813
2012-05-022.891.4121.913
2012-05-032.891.4127.113
2012-05-044.692.8127.713
2012-05-052.474.9125.813
2012-05-060.990.8111.313
2012-05-07092.1121.913
2012-05-081.990.7121.313
2012-05-090.990120.613
2012-05-102.892.1121.313
2012-05-110.990121.913
2012-05-12070127.113
2012-05-13090.7128.313
2012-05-144.690.7128.313
2012-05-150.990120.613
2012-05-160.990122.613
2012-05-171.991.4121.313
2012-05-180.99012013
2012-05-193.793.512913
2012-05-2014.892.81212.213
2012-05-21080125.113
2012-05-2208012011
2012-05-230.990123.213
2012-05-24095.6125.113
2012-05-25093.5127.713
2012-05-26091.4123.213
2012-05-27090120.613
2012-05-282.890122.311
2012-05-294.698.31213.513
2012-05-30082.1126.212
2012-05-318.394.9126.212
2012-06-016.592.81210.412
2012-06-020.991.4120.810
2012-06-030.990.7122.112
2012-06-045.691.4124.912
2012-06-05090123.512
2012-06-060.990120.810
2012-06-07180.7126.212
2012-06-08090122.112
2012-06-091.99012012
2012-06-10092.1124.912
2012-06-111.993.51212.911
2012-06-124.692.81215.312
2012-06-13090120.712
2012-06-140.990122.812
2012-06-151.992.81213.912
2012-06-164.870128.312
2012-06-17080122.812
2012-06-18180120.712
2012-06-19080.8114.212
2012-06-207.382.81211.112
2012-06-214.282.1126.912
2012-06-222.184.91211.112
2012-06-233.180.7127.612
2012-06-24080127.612
2012-06-252.184.91211.812
2012-06-262.180124.210
2012-06-27082.8125.612
2012-06-281.270.7123.512
2012-06-292.470.7122.112
2012-06-300801210.412
2012-07-01188.31216.712
2012-07-022.180123.310
2012-07-03080122.812
2012-07-046.280.7125.810
2012-07-05180.7122.812
2012-07-064.281.4126.912
2012-07-076.280122.812
2012-07-08080122.812
2012-07-093.182.112912
2012-07-10180.7123.512
2012-07-112.185.61223.612
2012-07-12186.21220.112
2012-07-13080120.712
2012-07-14080122.112
2012-07-1507012011
2012-07-16080121.511
2012-07-1708012011
2012-07-182.180.7124.511
2012-07-19181.4127.611
2012-07-2010.482.81215.211
2012-07-21670120.99
2012-07-222.1801212.58
2012-07-232.180.7124.210
2012-07-24080125.810
2012-07-25082.1128.310
2012-07-26182.1122.510
2012-07-27180122.510
2012-07-28082.81213.310
2012-07-294.285.61215.211
2012-07-3011.58012311
2012-07-31180121.511
2012-08-015.280.712311
2012-08-025.281.4125.612
2012-08-03182.1125.612
2012-08-04180122.112
2012-08-051.270.7124.912
2012-08-06671.4124.212
2012-08-075.660.7120.810
2012-08-08071.4120.712
2012-08-099.484.91223.310
2012-08-10080.7126.111
2012-08-113.184.2125.311
2012-08-122.182.8122.112
2012-08-13080120.712
2012-08-1408012012
2012-08-158.380124.212
2012-08-16080.7123.811
2012-08-174.280.7124.212
2012-08-189.484.9122.112
2012-08-193.182.11213.212
2012-08-200.9910.41213.912
2012-08-212.8910.4126.811
2012-08-221.991.4126.710
2012-08-231.991.4120.712
2012-08-240.990.71209
2012-08-259.390121.511
2012-08-265.692.8122.112
2012-08-27090127.510
2012-08-28180.7124.212
2012-08-293.793.512510
2012-08-306.5913.9121010
2012-08-316.59161214.411
2012-09-016.5931.91236.812
2012-09-027.4922.91218.812
2012-09-036.5961.81283.311
2012-09-044.6952.11266.712
2012-09-0517.6977.81293.812
2012-09-0611.1972.21210311
2012-09-078.3959.71286.112
2012-09-089.4856.21287.512
2012-09-0918.5928.51244.711
2012-09-1042.6940.3125011
2012-09-1154.6943.11227.812
2012-09-1248.1918.1122211
2012-09-1350.9928.51230.612
2012-09-1443.5925.71242.412
2012-09-15090124.28
2012-09-16097.61230.612
2012-09-1709161241.712
2012-09-183.7929.21277.311
2012-09-194.6911.81245.511
2012-09-208.3922.91234.111
2012-09-2116.799126.212
2012-09-2238913.21253.310
2012-09-2387935.41266.712
2012-09-2438.997.6126.212
2012-09-251.992.8124.69
2012-09-264.695.61210.412
2012-09-273.1814.61217.412
2012-09-283.794.9124.912
2012-09-29090.7120.712
2012-09-301.99012012
2012-10-014.697.6127.611
2012-10-023.790.71209
2012-10-037.494.9124.912
2012-10-045.692.8123.512
2012-10-056.590.7129.712
2012-10-062.895.6126.912
2012-10-07092.81218.112
2012-10-086.592.112311
2012-10-0913.992.1123.512
2012-10-100.992.8127.612
2012-10-111295.6129.712
2012-10-123.790.7123.512
2012-10-131.99012012
2012-10-141.990.7120.811
2012-10-153.790.712010
2012-10-161.993.5120.810
2012-10-171.990120.99
2012-10-181.990121.511
2012-10-190.991.4120.811
2012-10-201.990121.710
2012-10-213.673.5128.310
2012-10-221.992.81208
2012-10-230.99012012
2012-10-24090.7120.811
2012-10-251.992.1123.213
2012-10-264.690.712013
2012-10-27081.5116.413
2012-10-2819.4935.41263.513
2012-10-2927.89341252.613
2012-10-3086.1913.91218.911
2012-10-3143.8812.51212.510
2012-11-0129.694.21213.212
2012-11-0214.688.31215.211
2012-11-035.284.9123.512
2012-11-0416.7891213.310
2012-11-054.280.7121.412
2012-11-0639.682.8127.510
2012-11-079.486.21211.710
2012-11-0823.6615.31216.710
2012-11-099.766.2129.210
2012-11-106.964.2125.810
2012-11-1116.762.1128.39
2012-11-125.665.6128.310
2012-11-131.464.2120.811
2012-11-144.263.5125.311
2012-11-152.184.2126.811
2012-11-163.182.8121.511
2012-11-174.280120.712
2012-11-186.963.512011
2012-11-19060.8113.512
2012-11-2006011010
2012-11-214.874.5113.512
2012-11-225.283.8113.213
2012-11-236.28011012
2012-11-24090113.213
2012-11-255.660.8111.313
2012-11-265.696.1116.413
2012-11-270.992.3115.311
2012-11-284.691.5114.511
2012-11-291.997.6114.912
2012-11-302.186.7102.613
2012-12-013.180101.412
2012-12-02180100.613
2012-12-031.991.7104.513
2012-12-04083.3100.613
2012-12-053.79010013
2012-12-06090101.412
2012-12-079.763.3100.712
2012-12-085.660.8100.712
2012-12-094.263.3101.511
2012-12-109.767.5102.812
2012-12-111.465102.112
2012-12-12060.810012
2012-12-134.262.5100.613
2012-12-14061.272.112
2012-12-151.460.992.112
2012-12-1606070.811
2012-12-172.863.791.511
2012-12-1806180.810
2012-12-19062.18012
2012-12-202.86090.712
2012-12-211.463.18012
2012-12-220609012
2012-12-232.863.792.112
2012-12-24060.990.712
2012-12-252.862.89311
2012-12-26060.99012
2012-12-27061.994.212
2012-12-285.662.18012
2012-12-29062.47012
2012-12-300607012
2012-12-3106074.212