Skip to main content

Secondary navigation:





A STUDY OF NEW ENGLAND SEISMICITY

Quarterly Earthquake Report



October-December, 2004



New England

Seismic Network



Weston Observatory

381 Concord Road

Weston, MA 02493





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 # 04HQAG0020

Prepared by Anastasia Macherides Moulis

Email: macherid@bc.edu

January 3, 2005

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 04HQAG0020. The views and conclusions contained in this document are those of the authors andshould not be interpreted as necessarily representing the official policies,either expressed or implied, of the U.S. Government.

Quarterly Earthquake Report

October-December, 2004

Table of Contents

Introduction

The New England Seismic Network (NESN) is operated by the Weston Observatory (WES) of Boston College. 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 ofthe 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 October-December, 2004. 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 5 earthquakes that occurred within or near the network during this reporting period. Phase information for these earthquakes is included in this report.

Return to Table of Contents

Current Network Operation and Status

The New England Seismic Network of Weston Observatory of Boston College currently consists of 11 broadband three-component and 8 analog 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. The 11 stations consist 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 also maintains 8 SMA-1 strong-motion instruments in New England.

Return to Table of Contents

Seismicity

There were 5 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.

Return to Table of Contents

Data Management

Recent event locations are available at http://aki.bc.edu/cgi-bin/NESN/recent_events.pl. Waveform data are saved in Nanometrics, ASCII, and SEED formats and are available by contacting, Anastasia Macherides Moulis, via email. Earthquake lists can be found at www.bc.edu/research/westonobservatory/northeast/eqcatalogs/. Currently available on the Weston Observatory web page is the full catalog of northeastern U.S. earthquake activity to the present time. This will be updated as new Northeastern U.S. Seismic Network Quarterly Earthquake Reports are produced.

For more information on matters discussed in this report or general earthquake information (reports, maps, catalogs, etc.) consult our web site www.bc.edu/westonobservatory or contact:





Anastasia Macherides Moulis

Weston Observatory

381 Concord Road

Weston, MA 02493

Voice: 617-552-8325 / FAX: 617-552-8388 / Email: anastasia.macherides.1@bc.edu



Dina Smith

Weston Observatory

381 Concord Road

Weston, MA 02493

Voice: 617-552-8335 / FAX: 617-552-8388 / Email: dina.smith.1@bc.edu



Prof. John Ebel

Weston Observatory

381 Concord Road

Weston, MA 02493

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

Return to Table of ContentsReturn to Table of Contents



Explanation of Tables

Table 1: List of personnel operating the NESN

Table 2: List of Seismic and Strong Motion Stations

  1. Code = st ation 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. D ate = 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 se paration, 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 arr ival
    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 arriva l
  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 = sign al 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 = neares t station recording event
  3. Arrival Time = phase arrival time, Hr (hour):Mn (minute):Sec (second)

Return to Table of Contents

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@bc.edu
Anastasia Macherides Moulis Seismic Analyst 617-552-8325 macherid@bc.edu
vacant NESN Operator 617-552-8332 @bc.edu
Dina Smith Associate Director of Scientific

and Technical Operations
617-552-8335 dina.smith.1@bc.edu
Weston Observatory
617-552-8300

617-552-8388 (FAX)



Return to Table of Contents



TABLE 2




        

SEISMIC STATIONS OF THE NEW ENGLAND SEISMIC NETWORK

WES43.7050-72.3525Belchertown, MATroy, NYWESUMMWES42.3850WESYLEPQI46.6710
Code Lat Long Elev (m) Location Operator
BCX 42.3350 -71.1705 61.0 Chestnut Hill, MA WES
BRYW 41.9178 -71.5388 380.0 Smithfield, RI WES
FFD 43.4702 -71.6533 131.0 Franklin Falls Dam, NH
HNH -72.2860 180.0 Hanover, NH WES
QUA2 42.2789 168.0 WES
TRY * 42.7311 -73.6669 131.0
44.7100 -67.4583 35.0 Machias, ME WES
VT1 44.3317 -72.7536 410.0 Waterbury, VT WES
-71.3220 60.0 Weston, MA WES
WVL 44.5648 -69.6575 85.0 Waterville, ME
41.3100 -72.9269 10.0 New Haven, CT WES
-68.0168 175.0 Presque Isle, ME WES

* = not in operation during this quarter


        

STRONG MOTION STATIONS OF THE NEW ENGLAND SEISMIC NETWORK

SM2-73.10Newport, RISM4-71.30WESSM742.39-71.54WES
Code Lat Long Location Operator
SM1 44.90 -67.25 Dennysville, ME WES
44.49 Essex Junction, VT WES
SM3 41.45 -71.33 WES
42.38 -71.32 Weston, MA WES
SM5 42.66 Lowell, MA
SM6 42.30 -71.34 Natick, MA WES
Huds on, MA WES
SM8 44.48 -69.61 North Vassalboro, ME


Return to Table of Contents



TABLE 3




        

EVENTS IN NEW ENGLAND AND ADJACENT REGIONS


Date

M/D/Y
Time (UTC)

Hr:Mn:Sec
Lat Long Depth

(km)
Mag Int Location
10/06/2004 16:20:18.25 42.94 -71.96 26.26 2.0
NH, 26.2KM (16.3MI) E OF KEENE
10/08/2004 02:25:45.92 42.51 -71.47 5.00 2.4
MA, 4.25KM (2.64MI) SSE OF LITTLETON COMMON
10/08/2004 03:21:02.12 42.51 -71.47 0.9 -0.2
MA, 4.25KM (2.64MI) SSE OF LITTLETON COMMON
10/08/2004 12:38:13.04 42.51 -71.47 2.01 1.2
MA, 4.25KM (2.64MI) SSE OF LITTLETON COMMON
10/14/2004 09:36:03.58 41.39 -73.99 9.17 2.8
NY, 12.5 KM (7.77 MI) SOUTH OF NEWBURGH
* indicates Mc rather than Mn.

Return to Table of Contents

TABLE 4

EARTHQUAKE PHASE DATA LIST FOR EVENTS IN
NEW ENGLAND AND ADJACENT REGIONS

D4A06A.XX
SOUTHEAST MAINE CRUSTAL MODEL
04OCT06 NH, 26.2KM (16.3MI) E OF KEENE
  DATE     ORIGIN    LAT N    LONG W   DEPTH   MN  MC  ML GAP   RMS  ERH  ERZ Q
  41006 1620 18.25 42-56.34  71-57.80  26.26  1.6 2.0     157   .43  3.2  7.5 C
  STN  DIST AZM  RMK HRMN   SEC   TOBS   TCAL   RES   WT AMX PRX XMAG FMP FMAG
  HRV  58.4 145 EP 1 1620 27.85   9.60  10.24  -.67 1.22
                ES 1 1620 36.56  18.31  18.22   .04 1.24
 QUA2  80.0 204 EP 0 1620 32.08  13.83  13.32   .48 1.55  13 .10  1.3  61  2.0
                ES 3 1620 40.70  22.45  23.70 -1.31  .30
  WES  81.0 140 EP 0 1620 31.76  13.51  13.45   .05 1.58  34 .08  1.8  59  2.0
                ES 1 1620 42.50  24.25  23.95   .28 1.17
  HNH  89.1 343 EP 0 1620 32.98  14.73  14.61   .09 1.55
                ES 3 1620 42.04  23.79  26.01 -2.27  .02
  BRY 118.7 163 ES 3 1620 50.67  32.42  32.58  -.26  .36
D4A08A.XX
SOUTH & COASTAL NEW ENGLAND, CHIBURIS, 1979
04OCT08 MA, 4.25KM (2.64MI) SSE OF LITTLETON COMMON
  DATE     ORIGIN    LAT N    LONG W   DEPTH   MN  MC  ML GAP   RMS  ERH  ERZ Q
  41008  225 45.92 42-30.67  71-28.08   2.00   .0 2.0     148   .50  2.2  5.0 D
  STN  DIST AZM  RMK HRMN   SEC   TOBS   TCAL   RES   WT AMX PRX XMAG FMP FMAG
  HRV   7.4 266 EP 1  225 47.11   1.19   1.33  -.17 1.43
                ES 1  225 48.04   2.12   2.36  -.29 1.42
  WES  18.5 139 IPD0  225 49.26   3.34   3.14   .19 1.87               68  1.9
                ES 1  225 51.15   5.23   5.59  -.38 1.39
 QUA2  77.3 250 EP 3  226  1.62  15.70  12.83  2.84  .02               56  2.0
                ES 3  226 10.90  24.98  22.83  2.09  .21
  FFD 107.6 352 EP 3  226  4.95  19.03  17.84  1.17  .37
                ES 0  226 17.45  31.53  31.75  -.25 1.56
  HNH 148.4 333 EP 3  226 11.24  25.32  24.13  1.16  .33
                ES 0  226 28.87  42.95  42.95  -.06 1.41
D4A08B.XX
SOUTH & COASTAL NEW ENGLAND, CHIBURIS, 1979
04OCT08 MA, 4.25KM (2.64MI) SSE OF LITTLETON COMMON
  DATE     ORIGIN    LAT N    LONG W   DEPTH   MN  MC  ML GAP   RMS  ERH  ERZ Q
  41008  321  2.12 42-28.64  71-29.96    .90   .0 -.2     181   .14   .0   .0 A
  STN  DIST AZM  RMK HRMN   SEC   TOBS   TCAL   RES   WT AMX PRX XMAG FMP FMAG
  HRV   5.8 304 EP 0  321  3.09    .97   1.04  -.10 1.04                4  -.7
                 S 0  321  4.06   1.94   1.85   .03 1.05
  WES  17.9 125 EP 0  321  5.39   3.27   3.03   .23  .92               10   .3
                 S 0  321  7.39   5.27   5.39  -.14  .99
D4A08C.XX
SOUTH & COASTAL NEW ENGLAND, CHIBURIS, 1979
04OCT08 MA, 4.25KM (2.64MI) SSE OF LITTLETON COMMON
  DATE     ORIGIN    LAT N    LONG W   DEPTH   MN  MC  ML GAP   RMS  ERH  ERZ Q
  41008 1238 13.04 42-17.55  71-48.84   2.01   .0 1.2     192  1.78  5.9 **** D
  STN  DIST AZM  RMK HRMN   SEC   TOBS   TCAL   RES   WT AMX PRX XMAG FMP FMAG
  HRV  31.7  42 EP 0 1238 20.00   6.96   5.32  1.61 1.02               16   .9
                ES 0 1238 20.83   7.79   9.47 -1.73 1.01
  WES  41.8  76 EP 0 1238 22.77   9.73   6.99  2.73  .94               33  1.5
                ES 0 1238 24.05  11.01  12.45 -1.45 1.01
 QUA2  44.4 268 ES 0 1238 25.31  12.27  13.21  -.98 1.01
D4A14A.XX
SE OF NEW YORK, HUGHES & LUETGERT
04OCT14 NY, 12.5 KM (7.77 MI) SOUTH OF NEWBURGH
  DATE     ORIGIN    LAT N    LONG W   DEPTH   MN  MC  ML GAP   RMS  ERH  ERZ Q
  41014  936  3.58 41-23.33  73-59.41   9.17   .0 2.8      77   .40  1.5  2.7 C
  STN  DIST AZM  RMK HRMN   SEC   TOBS   TCAL   RES   WT AMX PRX XMAG FMP FMAG
 MANY  21.1 151 EP 3  936  6.57   2.99   3.54  -.57  .48
                ES 1  936  9.74   6.16   6.30  -.18 1.47
  TBR  33.6 215 EP 1  936  8.56   4.98   5.35  -.41 1.42
                ES 0  936 13.19   9.61   9.53   .01 1.91
  PAL  43.3 171 EP 0  936 10.38   6.80   6.78  -.01 1.88
                ES 0  936 15.79  12.21  12.08   .10 1.88
  GPD  57.1 224 EP 0  936 12.35   8.77   8.86  -.15 1.83
                ES 0  936 19.61  16.03  15.78   .15 1.83
 CPNY  66.4 178 EP 0  936 13.82  10.24  10.28  -.04 1.79
                ES 0  936 22.00  18.42  18.29   .13 1.79
 BRNJ  92.2 212 EP 1  936 18.31  14.73  14.18   .53 1.26
                ES 3  936 29.63  26.05  25.25   .78  .41
 QUA2 168.2  54 EP 3  936 32.50  28.92  25.77  3.12  .00              147  2.9
                ES 3  936 51.30  47.72  45.87  1.79  .18
 BINY 188.3 298 EP 0  936 32.49  28.91  28.74   .09 1.34
                ES 0  936 54.44  50.86  51.16  -.44 1.33
  BRY 212.4  74 EP 1  936 35.41  31.83  32.06  -.29  .94
                ES 2  936 60.19  56.61  57.06  -.56  .61
 ACCN 223.2   7 EP 2  936 36.54  32.96  33.39  -.50  .60
                ES 3  936 61.99  58.41  59.44 -1.14  .26
  HRV 236.9  58 EP 2  936 39.80  36.22  35.09  1.10  .53              131  2.9
                ES 1  936 65.90  62.32  62.46  -.20  .87
  WES 247.5  63 EP 3  936 37.37  33.79  36.40 -2.62  .00               92  2.6
                ES 0  936 68.75  65.17  64.79   .36 1.12
  HNH 293.0  29 EP 3  936 48.30  44.72  42.02  2.67  .00               97  2.7
                ES 3  936 80.99  77.41  74.79  2.56  .01
  MDV 297.5  13 EP 0  936 46.51  42.93  42.56   .34  .94
                ES 2  936 79.02  75.44  75.77  -.36  .46
  MIV 300.7   7 EP 3  936 45.83  42.25  42.96  -.77  .22
                ES 3  936 79.65  76.07  76.47  -.50  .23
  FFD 300.8  40 EP 2  936 47.70  44.12  42.97  1.13  .41
                ES 4  936 84.20  80.62  76.49  4.09  .00
Return to Table of Contents

TABLE 5

MICROEARTHQUAKES AND OTHER NON-LOCATABLE EVENTS

Date

Yr/Mo/Dy
Sta Arrival Time

Hr:Mn:Sec
None recorded this period.

Return to Table of Contents

NESN Station Map

Figure 1: Map of stations of the New England Seismic Network (NESN) in operation during the period of this report. Also included are other Northeast U.S. and Canadian seismic stations in operation during this period.

Return to Table of Contents

NESN Strong-Motion Station Map

Figure 2: Map of strong-motion stations of the New England Seismic Network (NESN) in operation during the period of this report.

Return to Table of Contents

NESN Quarterly Seismicity Map

Figure 3: Earthquake epicenters located by the NESN during the period of this report.

Return to Table of Contents

NESN Cumulative Seismicity Map

Figure 4: Seismicity for period October, 1975 - December, 2004.

Return to Table of Contents

Acknowledgments

Our map database has been developedin-house using ArcView and in part basemap data provided byESRI, 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 lengthmagnitude scale for New England, Earthquake Notes, 51, 15-22.

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

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

Return to Table of Contents