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A STUDY OF NEW ENGLAND SEISMICITY

Quarterly Earthquake Report

April - June, 2000



new england
seismic network
   

Weston Observatory
381 Concord Road
Weston, MA 02493
Earth Resources Lab
Massachusetts Institute of Technology
42 Carleton Street
Cambridge, MA 02142



NEW ENGLAND SEISMIC NETWORK

John E. Ebel, Principal Investigator
Weston Observatory
Dept. of Geology and Geophysics
Boston College
381 Concord Road
Weston, MA 02493
Email: ebel@bc.edu
Award # 1434-HQ-98-AG-01943
M. Nafi Toksöz, Principal Investigator
Earth Resources Lab
Dept. of Earth, Atmospheric, and Planetary Sciences
Massachusetts Institute of Technology
42 Carleton Street
Cambridge, MA 02142
Email: toksoz@mit.edu
Award # 1434-HQ-98-AG-01926

Prepared by Susan O'Connor
Email: dannolfo@bc.edu
November, 2001

for
United States Geological Survey
905 National Center
12201 Sunrise Valley Drive
Reston, Virginia 20192

Notice


Network operation supported by the U.S. Geological Survey (USGS), Department of the Interior, under USGS award number 1434-HQ-98-AG-01943 and award number 1434-HQ-98-AG-01926. The views and conclusions contained in this document are those of the authors and should not be interpreted as necessarily representing the official policies, either expressed or implied, of the U.S. Government.

Quarterly Earthquake Report
April - June, 2000

   

Table of Contents

Introduction

The New England Seismic Network (NESN) is operated collaboratively by the Weston Observatory (WES) of Boston College and the Earth Resources Lab (ERL) of the Massachusetts Institute of Technology. The mission of the NESN is to operate and maintain a regional seismic network with digital recording of seismic ground motions for the following purposes: 1) to determine the location and magnitude of earthquakes in and adjacent to New England and report felt events to public safety agencies, 2) to define the crust and upper mantle structure of the northeastern United States, 3) to derive the source parameters of New England earthquakes, and 4) to estimate the seismic hazard in the area.

This report summarizes the work of the NESN for the period April - June, 2000. It includes a brief summary of the network's equipment and operation, and a short discussion of data management procedures. A list of participating personnel is given in Table 1. There were 6 earthquakes that occurred within or near the network during this reporting period. Phase information for these earthquakes is included in this report.

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Current Network Operation and Status

The New England Seismic Network currently consists of 13 broadband three-component, 4 short-period vertical, and 8 strong-motion stations. The coordinates of the stations are given in Table 2, and maps of the weak- and strong-motion networks are shown in Figures 1 and 2, respectively.

WES operates 12 stations with broadband instruments consisting of Guralp CMG-40T three-component sensors. Ground motions recorded by these sensors are digitized at 100 sps with 16-bit resolution. Additional gain-ranging provides 126 dB dynamic range. These stations are operated in dialup mode with waveform segments of suspected events transmitted in digital mode to Weston Observatory for analysis and archiving. WES is continuing to upgrade its recording stations with 2 more broadband instruments scheduled for installation in 2000. WES also maintains 8 SMA-1 strong-motion instruments in New England.

ERL at MIT currently operates 4 short-period stations, all located within 100 km of Boston. The short- period instruments have 1.0 Hz L4C vertical seismometers. Data recorded by these seismometers is transmitted continuously in analog mode to ERL and digitized (12-bit) into a PC at 50 sps. A data acquisition program on the PC triggers on events detected in the short-period data streams and saves them to a disk for manual analysis. Station WFM also has a new three-component, high dynamic range instrument. The instrument has a CMG-40T sensor and transmits 3-channel, 24-bit data at 100 sps continuously to a central processor (Pentium PC) at ERL. Waveform windows of suspected events are extracted from the data stream, analyzed and archived with the short-period data. WES and ERL record some stations in analog format on helicorders to provide additional data for analysis.

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Seismicity

There were 6 earthquakes that occurred in or adjacent to the NESN during this reporting period. A summary of the location data is given in Table 3. Figure 3 shows the locations of these events. Figure 4 shows the locations of all events since the beginning of network operation in October, 1975.

Table 4 gives the station phase data and detailed hypocenter data for each event listed in Table 3. In addition to NESN data, arrival time and magnitude data sometimes are contributed for seismic stations operated by the Geological Survey of Canada (GSC), the Lamont-Doherty Cooperative Seismographic Network., and the US National Seismic Network. Final locations for this section were computed using the program HYPO78. For regional events (those too far from the NESN to obtain accurate locations and magnitudes) phase data are given for NESN stations, but the entry in Table 3 lists the hypocenter and geographic location information adopted from the authoritative network. Accordingly, the epicenter is plotted on the maps using the entry from Table 3.

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Data Management

Recent event locations are available via FTP at: SEISMOEAGLE.BC.EDU. Waveform data are saved in Nanometrics, ASCII, and SEED formats and are available via SEISMOEAGLE.BC.EDU or through personal contact. Earthquake lists can be fingered at QUAKE@SEISMOEAGLE.BC.EDU. Weston Observatory maintains two web pages with information about local earthquakes: "http://www.bc.edu:80/bc_org/avp/cas/wesobs/" and "http://seismoeagle.bc.edu/". The latter page is still under contruction. Currently available on the seismoeagle web page is the full catalog of northeastern U.S. earthquake activity to 1992. This will be updated as new Northeastern U.S. Seismic Network Bulletins are produced.

MIT/ERL provides two internet utilities, the MIT/ERL web-site ("www-erl.mit.edu/NESN/homepage.html") and an anonymous FTP directory, to distribute seismic data. SESAME (Seismic Event Server at MIT/ERL) is the web data server that distributes catalogs, reports, earthquake bulletins, and epicenter and station maps (including an archive of recent seismic events). The FTP site, named "sunda.mit.edu", is the current facility available to download waveform data recorded by the MIT NESN. The client machine IP number must be forwarded to us for the client to gain access to the anonymous FTP directory. After logging on, the user changes directories to "pub/seismic". Waveforms of individual events for the period April 1995 through the present are accessed as Unix-compressed SAC files, through the anonymous FTP directory. A "readme" file offers further explanation about the data. Older waveform data in SAC format (1981 - March 1995) will be made available on the FTP site upon request.

For more information on matters discussed in this report or general earthquake information (reports, maps, catalogs, etc.) consult our web-sites www-erl.mit.edu/NESN and www.bc.edu:80/bc_org/avp/cas/wesobs/ or contact:

Robert Cicerone
MIT Earth Resources Lab
42 Carleton Street
Cambridge, MA 02142


Voice: 617-253-7863 / FAX: 617-253-6385 / Email: cicerone@erl.mit.edu


Prof. John Ebel
Weston Observatory
381 Concord Road
Weston, MA 02493


Voice: 617-552-8319 / FAX: 617-552-8388 / Email: ebel@bc.edu

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Explanation of Tables

Table 1: List of personnel operating the NESN

Table 2: List of Seismic and Strong Motion Stations

  1. Code = station name
  2. Lat = station latitude, degrees north
  3. Long = station longitude, degrees west
  4. Elev = station elevation in meters
  5. Location = geographic location
  6. Operator = network operator

Table 3: Earthquake Hypocenter List

  1. Date = date event occurred, Yr (year)/Mo (month)/Dy (day)
  2. Time = origin time of event, Hr (hour):Mn (minute):Sec (second)
    in UCT (Universal Coordinated Time, same as Greenwich Mean Time)
  3. Lat = event location, latitude north in degrees
  4. Long = event location, longitude west in degrees
  5. Depth = event depth in kilometers
  6. Mag = event magnitude
  7. Int = event epicentral intensity
  8. Location = event geographic location

Table 4: Earthquake detailed hypocenter and phase data list

Table Header: detailed hypocenter data

  1. Geographic location
  2. DATE = date event occurred, yr/mo/dy (year/month/day)
  3. ORIGIN = event origin time (UCT) in hours, minutes, and seconds
  4. LAT N = latitude north in degrees and minutes
  5. LONG W = longitude west in degrees and minutes
  6. DEPTH = event depth in kilometers
  7. MN = Nuttli Lg phase magnitude with amplitude divided by period
  8. MC = signal duration (coda) magnitude
    WES: 2.23 Log(FMP) + 0.12Log(Dist) - 2.36 (Rosario, 1979)
    MIT: 2.21 Log(FMP) - 1.7 (Chaplin et al., 1980)
  9. ML = local magnitude
    WES: calculated from Wood-Anderson seismograms (Ebel, 1982)
    GSC (Geological Survey of Canada): Richter Lg magnitude
  10. GAP = largest azimuthal separation, in degrees, between stations
  11. RMS = root mean square error of travel time residual in seconds
  12. ERH = standard error of epicenter in kilometers
  13. ERZ = standard error of event depth in kilometers
  14. Q = solution quality of hypocenter
    A = excellent
    B = good
    C = fair
    D = poor

Table Body: earthquake phase data

  1. STN = station name
  2. DIST = epicentral distance in kilometers
  3. AZM = azimuthal angle in degrees measured clockwise between true north and vector pointing from epicenter to station
  4. Description of onset of phase arrival
    I = impulsive
    E = emergent
  5. R = phase
    P = first P arrival
    S = first S arrival
  6. M = first motion direction of phase arrival
    U = up or compression
    D = down or dilatation
  7. K = weight of arrival
    0 = full weight (1.0)
    1 = 0.75 weight
    2 = 0.50 weight
    3 = 0.25 weight
    4 = no weight (0.0)
  8. HRMN = hour and minute of phase arrival
  9. SEC = second of phase arrival
  10. TCAL = calculated travel time of phase in seconds
  11. RES = travel time residual (error) of phase arrival
  12. WT = weight of phase used in hypocentral solution
  13. AMX = peak-to-peak ground motion, in millimicrons, of the maximum envelope amplitude of vertical-component signal, corrected for system response
  14. PRX = period in seconds of the signal from which amplitude was measured
  15. XMAG = Nuttli magnitude recorded at station
  16. FMP = signal duration (coda), in seconds, measured from first P arrival
  17. FMAG = coda magnitude recorded at station

Table 5: Microearthquakes and other non-locatable events

  1. Date = date event occurred, Yr (year)/Mo (month)/Dy (day)
  2. Sta = nearest station recording event
  3. Arrival Time = phase arrival time, Hr (hour):Mn (minute):Sec (second)

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TABLE 1


   

WESTON OBSERVATORY PERSONNEL

Name Network Position voice phone email address
John E. Ebel Principal Investigator 617-552-8319 ebel@bc.edu
Alan Kafka Research Seismologist 617-552-8300 kafka@bcvms.bc.edu
Susan O'Connor Seismic Analyst 617-552-8337 dannolfo@bc.edu
Edward Johnson Project Engineer 617-552-8332 johnson@bcvms.bc.edu
Patricia Tassia Administrative Secretary 617-552-8311 tassia@bcvms.bc.edu
W. Richard Ott, S.J. Assistant to the Director 617-552-8335 ottwi@mail1.bc.edu
Weston Observatory
617-552-8300
617-552-8388 (FAX)


   

MIT/ERL PERSONNEL

Name

Network Position voice phone email address
M. Nafi Toksöz Principal Investigator 617-253-7852 toksoz@mit.edu
Robert Cicerone Research Seismologist 617-253-7863 cicerone@erl.mit.edu
Heather Hooper Seismic Analyst 617-253-6290
Sara Brydges Administrator 617-253-7797 sara@erl.mit.edu
Earth Resources Lab
617-253-8027
617-253-6385 (FAX)



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TABLE 2


   

SEISMIC STATIONS OF THE NEW ENGLAND SEISMIC NETWORK

Code Lat Long Elev (m) Location Operator
BCX 42.3350 -71.1705 61.0 Chestnut Hill, MA WES
BRY 41.9178 -71.5388 380.0 Smithfield, RI WES
DNH 43.1225 -70.8948 24.0 Durham, NH MIT
DXB 42.0610 -70.6992 8.0 Duxbury, MA MIT
GLO 42.6403 -70.7272 15.2 Gloucester, MA MIT
HNH 43.7050 -72.2860 180.0 Hanover, NH WES
MIM 45.2436 -69.0403 140.0 Milo, ME WES
NH1 43.5473 -71.5743 402.0 Sanbornton, NH WES
QUA2 42.2789 -72.3525 168.0 Belchertown, MA WES
TRY 42.7311 -73.6669 131.0 Troy, NY WES
VT1 44.3317 -72.7536 410.0 Waterbury, VT WES
WES 42.3850 -71.3220 60.0 Weston, MA WES
WFM 42.6106 -71.4906 87.5 Westford, MA MIT
WVL 44.5648 -69.6575 85.0 Waterville, ME WES
YLE 41.3100 -72.9269 914.0 New Haven, CT WES
PQI 46.6710 -68.0168 175.0 Presque Isle, ME WES
   

STRONG MOTION STATIONS OF THE NEW ENGLAND SEISMIC NETWORK

Code Lat Long Location Operator
SM1 44.90 -67.25 Dennysville, ME WES
SM2 44.49 -73.10 Essex Junction, VT WES
SM3 41.45 -71.33 Newport, RI WES
SM4 42.38 -71.32 Weston, MA WES
SM5 42.66 -71.30 Lowell, MA WES
SM6 42.30 -71.34 Natick, MA WES
SM7 42.39 -71.54 Hudson, MA WES
SM8 44.48 -69.61 North Vassalboro, ME WES

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TABLE 3


   

EARTHQUAKE HYPOCENTER LIST
NEW ENGLAND AND ADJACENT REGIONS
April - June, 2000

Date
Yr/Mo/Dy
Time
Hr:Mn:Sec
Lat Long Depth
(km)
Mag Int Location
2000/04/16 18:59:13.99 44.0060 -74.2522 5.00 2.2
NY, ADIRONDACK MTNS
2000/04/20 08:46:55.54 43.9580 -74.2583 5.00 3.8
NY, 40 KM SSW OF SARNAC LAKE
2000/06/08 20:35:15.76 42.5166 -71.4972 4.15 1.4*
MA, LITTLETON
2000/06/15 09:25:55.53 47.5798 -69.7612 9.13 3.5
PQ, CHARLEVOIX
2000/06/16 04:02:53.39 42.1025 -72.8162 9.82 3.0
MA, 6.5 KM SW OF WESTFIELD
2000/06/29 08:15:28.10 46.5653 -70.1070 5.00 2.4
PQ, QUEBEC CITY REGION
* indicates Mc rather than Mn.

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TABLE 4

EARTHQUAKE PHASE DATA LIST
NEW ENGLAND AND ADJACENT REGIONS
April - June, 2000

 NORTHERN NY AND ADIRONDACKS
 00APR16 NY, ADIRONDACK MTNS (E OF CATLIN LAKE)

  DATE     ORIGIN    LAT N    LONG W   DEPTH   MN  MC  ML GAP   RMS  ERH  ERZ Q
    416 1859 13.99 44- 0.39  74-15.13   5.00  2.2         176  0.31  1.9  2.2 C

  STN  DIST AZM  RMK HRMN   SEC   TOBS   TCAL   RES   WT AMX PRX XMAG FMP FMAG
  PTN  85.8 317  P 0 1859 27.01  13.02  13.24 -0.27 1.75
                 S 0 1859 37.94  23.95  23.58  0.30 1.73
  BGR  91.9 354 IPC1 1859 27.82  13.83  14.17 -0.34 1.27
                 S 2 1859 39.70  25.71  25.23  0.48 0.80
  HNH 161.5 102 EPC0 1859 39.05  25.06  24.72  0.31 1.45  24 .14  2.0
                 S 2 1859 57.54  43.55  44.00 -0.51 0.66
  GAC 212.0 333  P 1 1859 45.75  31.76  31.96 -0.20 0.95
  MOQ 214.8  48  P 1 1859 46.32  32.33  32.31 -0.12 0.96
 QUA2 246.5 141 EPC0 1859 50.82  36.83  36.22  0.58 0.97  66 .35  2.5
                 S 2 1859 78.43  64.44  64.47 -0.09 0.58
  TRQ 247.4 354  P 0 1859 50.28  36.29  36.33 -0.04 1.15
  WES 298.6 127 EP 4 1859 60.78  46.79  42.66  4.12 0.00  14 .18  2.2
                 S 4 1859 93.44  79.45  75.93  3.50 0.00
  GRQ 315.3 336  P 1 1859 58.39  44.40  44.71 -0.31 0.65
  DPQ 318.9  21  P 1 1859 59.02  45.03  45.16 -0.13 0.66
  BRY 320.6 136  S 2 1859 94.78  80.79  80.76  0.03 0.44  11 .16  2.2
  MIM 436.1  72 EP 4 1859 82.87  68.88  59.62  9.24 0.00   5 .23  2.1
  PQI 571.7  59  S 4 1859 72.70  58.71 135.94-77.29 0.00

NORTHERN NY AND ADIRONDACKS
 00APR20 NY, 40 KM SSW OF SARNAC LAKE

  DATE     ORIGIN    LAT N    LONG W   DEPTH   MN  MC  ML GAP   RMS  ERH  ERZ Q
    420  846 55.54 43-57.48  74-15.50   5.00  3.8 3.5      77  0.54  1.3  1.9 D

  STN  DIST AZM  RMK HRMN   SEC   TOBS   TCAL   RES   WT AMX PRX XMAG FMP FMAG
  PTN  89.5 320 EPC0  847  9.41  13.87  13.81  0.02 2.01
                 S 0  847 20.63  25.09  24.58  0.44 2.01
  BGR  97.2 355 IPC0  847 10.35  14.81  14.98 -0.17 1.98
                 S 0  847 22.03  26.49  26.66 -0.17 1.98
 MSNY 125.2 337 EPD0  847 14.57  19.03  19.22 -0.20 1.86
                 S 0  847 29.54  34.00  34.20 -0.22 1.86
  VT1 127.4  71  PD0  847 15.24  19.70  19.56  0.12 1.85
                 S 2  847 30.58  35.04  34.82  0.19 0.92
  WBO 141.3 325 EPD0  847 17.14  21.60  21.65 -0.05 1.79
                 S 0  847 34.31  38.77  38.54  0.23 1.79
  HNH 161.2 100  PD0  847 20.51  24.97  24.68  0.26 1.70
                 S 1  847 39.07  43.53  43.93 -0.46 1.28
  MNT 178.9  16  P 0  847 22.53  26.99  27.35 -0.37 1.62
 LBNH 189.4  80 IPC0  847 25.00  29.46  28.94  0.46 1.58
                 S 0  847 46.80  51.26  51.52 -0.37 1.58
  OTT 197.0 324  P 0  847 25.65  30.11  30.10  0.01 1.54
  GAC 216.7 334  P 0  847 28.22  32.68  32.54  0.14 1.46
  MOQ 219.0  47  P 1  847 28.74  33.20  32.83  0.23 1.09
 QUA2 242.6 140  PD1  847 31.94  36.40  35.74  0.62 1.01
                 S 3  847 60.88  65.34  63.62  1.66 0.31
  TRQ 252.7 355  P 0  847 32.75  37.21  36.99  0.22 1.30
 LSCT 267.0 162  P 0  847 35.00  39.46  38.75  0.66 1.24
                 S 0  847 63.57  68.03  68.98 -1.04 1.20
  DNH 287.5 109 EP 0  847 33.50  37.96  41.28 -3.32 0.17              321  3.6
                 S 0  847 71.50  75.96  73.47  2.48 0.77
  WES 295.8 126  PD0  847 37.77  42.23  42.31 -0.09 1.11 373 .12  3.8
                 S 4  847 63.92  68.38  75.31 -6.95 0.00
  TBR 312.9 179  P 0  847 40.17  44.63  44.42  0.17 1.04
                 S 0  847 74.28  78.74  79.06 -0.39 1.04
  BRY 317.3 136  PD0  847 40.56  45.02  44.97  0.05 1.02 554 .25  3.7
                 S 4  847 80.88  85.34  80.04  5.30 0.00
  GRQ 320.0 337  P 2  847 41.39  45.85  45.30  0.55 0.50
  GLO 321.8 117 EP 0  847 40.30  44.76  45.51 -0.75 0.99              252  3.5
  DPQ 324.1  21  P 0  847 41.07  45.53  45.80 -0.27 0.99
                 S 2  847 76.13  80.59  81.52 -0.93 0.48
  DXB 358.7 126 EP 0  847 45.30  49.76  50.07 -0.31 0.84              254  3.5
                 S 0  847 91.00  95.46  89.12  6.33 0.00
  QCQ 390.8  37  P 0  847 49.54  54.00  54.04 -0.04 0.70
  EFO 419.9 257  P 2  847 52.76  57.22  57.63 -0.41 0.28
                 S 4  847 60.58  65.04 102.58-37.54 0.00
  EEO 481.2 308  P 0  848  0.58  65.04  65.20 -0.16 0.30
                 S 4  848 46.99 111.45 116.05 -4.60 0.00
  A11 483.4  41  P 0  848  1.02  65.48  65.47  0.00 0.29
                 S 3  848 53.32 117.78 116.53  1.23 0.07
  A54 490.9  38  P 0  848  1.66  66.12  66.39 -0.33 0.26
                 S 0  848 53.53 117.99 118.18 -0.30 0.26
  LMQ 502.7  37  P 0  848  2.98  67.44  67.85 -0.48 0.21
                 S 1  848 55.48 119.94 120.77 -0.96 0.15
  DAQ 502.9  28  P 1  848  2.95  67.41  67.87 -0.63 0.15
                 S 4  848 57.56 122.02 120.82  0.92 0.00
  A16 511.6  40  P 0  848  4.44  68.90  68.95 -0.05 0.17
                 S 0  848 58.22 122.68 122.72 -0.05 0.17
  A61 526.7  38  P 0  848  5.97  70.43  70.81 -0.39 0.10
  A21 547.3  40  P 0  848  8.87  73.33  73.35 -0.02 0.00
                 S 0  848 66.22 130.68 130.57  0.11 0.00
  A64 547.6  38  P 0  848  8.66  73.12  73.39 -0.29 0.00
  PQI 575.0  58  PU4  848 67.84 132.30  76.77 55.50 0.00 489 .61  3.9
                 S 4  848 94.09 158.55 136.66 21.84 0.00
  CNQ 760.0  39  P 0  848 34.76  99.22  99.61 -0.42 0.00
  LMN 775.7  74  P 4  848 34.83  99.29 101.56 -2.27 0.00
  GSQ 778.2  45  P 0  848 36.82 101.28 101.87 -0.60 0.00
  ICQ 817.4  41  P 0  848 41.39 105.85 106.70 -0.86 0.00
  MNQ 840.7  30  P 3  848 43.44 107.90 109.58 -1.68 0.00
  SMQ 902.3  39  P 3  848 51.64 116.10 117.18 -1.14 0.00

SOUTH & COASTAL NEW ENGLAND, CHIBURIS, 1979
 00JUN08 MA, LITTLETON

  DATE     ORIGIN    LAT N    LONG W   DEPTH   MN  MC  ML GAP   RMS  ERH  ERZ Q
    608 2035 15.76 42-31.00  71-29.83   4.15  0.9 1.4     133  0.49  3.2 16.7 C

  STN  DIST AZM  RMK HRMN   SEC   TOBS   TCAL   RES   WT AMX PRX XMAG FMP FMAG
  WFM  10.4   3 EP 0 2035 17.64   1.88   1.90 -0.03 1.14               50  1.6
                ES 0 2035 18.76   3.00   3.38 -0.40 1.13
  WES  20.5 136 EP 0 2035 19.40   3.64   3.52  0.11 1.12   7 .08  0.4  32  1.3
                ES 0 2035 21.76   6.00   6.26 -0.28 1.10
  BRY  66.6 183 EP 4 2035 29.27  13.51  11.08  2.43 0.00  13 .16  1.2
                ES 0 2035 35.56  19.80  19.73  0.07 1.02
 QUA2  75.2 249 EP 0 2035 29.95  14.19  12.51  1.65 0.50   8 .10  1.1
                ES 0 2035 37.84  22.08  22.26 -0.23 1.00

NORTHWEST MAINE CRUSTAL STRUCTURE
 00JUN15 PQ, CHARLEVOIX

  DATE     ORIGIN    LAT N    LONG W   DEPTH   MN  MC  ML GAP   RMS  ERH  ERZ Q
    615  925 55.53 47-34.79  69-45.67   9.13  3.5 2.8     283  0.46 50.1 59.6 D

  STN  DIST AZM  RMK HRMN   SEC   TOBS   TCAL   RES   WT AMX PRX XMAG FMP FMAG
  PQI 166.6 127 IPD0  926 22.20  26.67  26.61  0.04 2.23 307 .16  3.1 129  2.8
                ES 0  926 43.00  47.47  47.36  0.06 2.23
  MIM 265.5 168 EPD3  926 35.30  39.77  38.82  0.93 0.40  65 .11  3.0
                ES 1  926 64.78  69.25  69.11  0.11 1.33
  WVL 339.1 179 EPD2  926 42.45  46.92  47.90 -0.99 0.63  78 .19  3.0 117  2.9
                ESD3  926 79.20  83.67  85.27 -1.61 0.13
  VT1 429.1 213 EPD4  927 10.77  75.24  59.01 16.21 0.00 363 .09  4.5
                ESD4  927 50.38 114.85 105.04  9.77 0.00
  HNH 473.6 205 EPD3  927  1.64  66.11  64.51  1.58 0.06  35 .21  3.0
                ES 4  927 64.30 128.77 114.82 13.90 0.00
  WES 590.3 192 ESD4  928 45.28 169.75 140.48 29.25 0.00  34 .39  2.9
  BCX 593.4 191 ES 4  928 44.04 168.51 141.15 27.36 0.00  33 .28  3.1
  QUA 605.4 200 ES 4  928 48.86 173.33 143.79 29.49 0.003637 .33  5.1

SOUTH & COASTAL NEW ENGLAND, CHIBURIS, 1979
 00JUN16 MA, 6.5 KM SW OF WESTFIELD

  DATE     ORIGIN    LAT N    LONG W   DEPTH   MN  MC  ML GAP   RMS  ERH  ERZ Q
    616  4 2 53.39 42- 6.15  72-48.97   9.82  3.0 3.1     146  0.49  1.6  1.7 C

  STN  DIST AZM  RMK HRMN   SEC   TOBS   TCAL   RES   WT AMX PRX XMAG FMP FMAG
 QUA2  43.0  63 IPD0  4 3  0.77   7.38   7.34  0.01 2.23
                ES 1  4 3  5.83  12.44  13.06 -0.67 1.58
  YLE  88.5 186 EP 0  4 3  7.98  14.59  14.53  0.06 2.03 238 .12  2.6 101  2.5
                ES 1  4 3 18.77  25.38  25.87 -0.49 1.47
  BRY 107.8 101 EPD2  4 3 11.49  18.10  17.46  0.64 0.92              125  2.7
                ES 2  4 3 24.69  31.30  31.08  0.22 0.97
  WFM 122.9  63 EP 0  4 3 13.59  20.20  19.75  0.44 1.84              210  3.2
                ES 1  4 3 29.13  35.74  35.15  0.57 1.35
  WES 127.3  76 EPC1  4 3 14.23  20.84  20.42  0.40 1.38 592 .08  3.4 217  3.2
                ES 1  4 3 29.13  35.74  36.35 -0.63 1.32
  BCX 138.4  79 IP 1  4 3 16.13  22.74  22.10  0.64 1.29              230  3.3
                ES 2  4 3 32.03  38.64  39.33 -0.70 0.84
  GLO 182.1  71 EP 2  4 3 20.90  27.51  28.09 -0.59 0.77
                ES 3  4 3 42.38  48.99  50.01 -1.02 0.31
  HNH 183.3  14 EP 3  4 3 21.09  27.70  28.24 -0.57 0.39 142 .08  3.1 228  3.3
                ES 3  4 3 43.04  49.65  50.27 -0.67 0.38
  DNH 194.2  54 EP 1  4 3 22.70  29.31  29.59 -0.28 1.16
                ES 1  4 3 46.34  52.95  52.67  0.28 1.16
  VT1 247.7   1 EP 4  4 3 34.53  41.14  36.20  4.92 0.00              129  2.9
                ES 4  4 3 62.49  69.10  64.43  4.63 0.00
 LBNH 248.2  17 EP 3  4 3 29.01  35.62  36.26 -0.71 0.31              225  3.3
                ES 4  4 3 56.18  62.79  64.55 -1.87 0.00
  MOQ 359.5   7  P 0  4 3 43.81  50.42  50.00  0.28 0.83
  WVL 371.5  43 EP 4  4 3 47.64  54.25  51.48  2.75 0.00              187  3.3
                ES 4  4 3 98.65 105.26  91.64 13.60 0.00
  MNT 383.3 350  P 0  4 3 46.57  53.18  52.94  0.24 0.73
  GAC 453.7 332  P 0  4 3 55.60  62.21  61.63  0.58 0.41
  MIM 463.1  41 EP 3  4 3 55.04  61.65  62.79 -1.16 0.06              145  3.1
  TRQ 478.4 343  P 0  4 3 58.85  65.46  64.68  0.78 0.28
  PQI 635.5  37 EP 4  4 4 29.57  96.18  84.07 12.07 0.00              128  3.2

SOUTHEAST MAINE CRUSTAL MODEL
 00JUN29 PQ, QUEBEC CITY REGION

  DATE     ORIGIN    LAT N    LONG W   DEPTH   MN  MC  ML GAP   RMS  ERH  ERZ Q
    629  815 28.10 46-33.92  70- 6.42   5.00  2.4         237  0.39  8.6 16.3 D

  STN  DIST AZM  RMK HRMN   SEC   TOBS   TCAL   RES   WT AMX PRX XMAG FMP FMAG
  PQI 160.6  86 EP 4  815 49.54  21.44  25.59 -4.18 0.00  47 .13  2.3
                ES 3  815 73.73  45.63  45.55  0.03 0.86
  MIM 168.6 151 EP 4  815 51.24  23.14  26.58 -3.46 0.00  56 .11  2.5
                ES 2  815 75.59  47.49  47.31  0.15 1.69
  WVL 228.8 171 EP 4  816  8.04  39.94  34.01  5.92 0.00  20 .09  2.4
                ES 3  816 27.26  59.16  60.54 -1.40 0.35
  VT1 323.4 220 ES 4  816 37.09  68.99  81.32-12.36 0.00
  HNH 361.1 208 EP 1  816 18.59  50.49  50.35  0.11 1.26  17 .15  2.6
                ES 2  816 57.86  89.76  89.62  0.09 0.84


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TABLE 5


   

MICROEARTHQUAKES AND OTHER NON-LOCATABLE EVENTS

Date
Yr/Mo/Dy
Sta Arrival Time
Hr:Mn:Sec
None recorded this period.


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NESN Station Map

Figure 1: Map of stations of the New England Seismic Network (NESN) in operation during period April - June, 2000. Also included are the US National Seismic Network stations operating in New England during this period.

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NESN Strong-Motion Station Map

Figure 2: Map of strong-motion stations of the New England Seismic Network (NESN) in operation during period April - June, 2000.

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NESN Quarterly Seismicity Map

Figure 3: Earthquake epicenters located by the NESN during period April - June, 2000.

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NESN Cumulative Seismicity Map

Figure 4: Seismicity for period October, 1975 - June, 2000.

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Acknowledgments

We would like to thank the Undergraduate Research Opportunities Program (UROP) of MIT for its support to the network. Our map database has been developed in-house using ARCINFO and in part basemap data provided by ESRI, Inc. (Arcdata Online), USGS GTOPO30 Elevation Data, and TIGER/Line '94, '95, and '97 (US Census Bureau) spatial data.

References

Chaplin, M.P., Taylor, S.R., and Toksöz, M.N. (1980), A coda length magnitude scale for New England, Earthquake Notes, 51, 15-22.

Ebel, J.E. (1982), ML measurements for northeastern United States earthquakes, Bull. Seism. Soc. Am., 72, 1367-1378.

Rosario, M. (1979), A coda duration magnitude scale for the New England Seismic Network, Master's Thesis, Boston College, 82 pp.

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