Hello,

With reference to an event listed on the EMSC website (BGS location parameters below), we conclude from the analysis of data from BGS seismograph sites that this event has all the characteristics of an underwater explosion and is not a natural tectonic earthquake.


The following BGS preliminary information is available for this event:

DATE			:	18 August 2005
ORIGIN TIME		:	16:11 19.7s UTC
LAT/LONG		:	49.678o North / 1.652o West
DEPTH			:	0 km (fixed)
MAGNITUDE		:	2.0 ML
LOCALITY		:	Off Cherbourg Peninsula

BEGIN GSE2.1
MSG_TYPE DATA
MSG_ID 20050818_161130.320 GBR_NDC
DATA_TYPE ARRIVAL:AUTOMATIC GSE2.1
Net       Sta   BeamID          Date       Time      Phase     Azim  Slow   SNR       Amp   Per   STA   Dur Author       DetID
GBR_NDC   JLP                2005/08/18 16:11:30.320 P                                                                        
GBR_NDC   JRS                2005/08/18 16:11:31.170 P                                                                        
GBR_NDC   JVM                2005/08/18 16:11:31.400 P                                                                        
GBR_NDC   JSA                2005/08/18 16:11:31.680 P                                                                        
GBR_NDC   DCO                2005/08/18 16:11:47.820 P                                                                        
GBR_NDC   DYA                2005/08/18 16:11:49.440 P                                                                        
GBR_NDC   DYA                2005/08/18 16:12:10.660 S                               36.9  0.16                               
GBR_NDC   DYA                2005/08/18 16:12:12.070 AML                             36.9  0.16                               
GBR_NDC   DYA                2005/08/18 16:12:12.420 AML                             20.0  0.19                               
GBR_NDC   MCH                2005/08/18 16:11:59.180 P                                                                        
GBR_NDC   MCH                2005/08/18 16:12:29.480 S                                                                        
GBR_NDC   MCH                2005/08/18 16:12:36.800 AML                              4.0  0.30                               
GBR_NDC   MCH                2005/08/18 16:12:38.790 AML                              4.0  0.51                               
STOP

2005  818 1611 19.7 LE 49.678  -1.652  0.0F BGS  7 0.2 2.0LBGS                1
 GAP=230        0.25       2.8    19.7  0.0  0.4420E+02  0.0000E+00  0.0000E+00E
 4.00  0.00/ 5.90  2.52/ 6.45  7.55/ 7.00 18.87/ 8.00 34.15/                  93
  15. 100. 300. 1.73                                                          A3
 2005-08-18-1611-30S.SESD__012                                                 6
 2005-08-18-1611-30S.DVSD__007                                                 6
 2005-08-18-1611-12S.JRQ___013                                                 6
 2005-08-18-1611-35S.MCSD__006                                                 6
 2005-08-18-1612-37S.LEQ___014                                                 6
 2005-08-18-1611-50S.CNQ___016                                                 6
 ACTION:REE 05-08-19 08:25 OP:gdf  STATUS:               ID:20050818161210     I
 U/W-CHERBOURG PENINSUL                                                       23
                                                                               3
 STAT SP IPHASW D HRMM SECON CODA AMPLIT PERI AZIMU VELO SNR AR TRES W  DIS CAZ7
 JLP  SZ EP       1611 30.32                              38     0.010 57.9 215 
 JRS  SZ EP       1611 31.17                              38     0.110 62.8 211 
 JVM  SZ IP     C 1611 31.40                              38    -0.110 65.2 218 
 JSA  SZ EP       1611 31.68                              38     0.010 66.3 215 
 DCO  SZ EP       1611 47.82                              35    -0.1 6  174 295 
 DYA  EZ EP       1611 49.44                              30     0.3 6  184 298 
 DYA  EN ES   3   1612 10.66        36.9 0.16             30     0.0 1  184 298 
 DYA  EN  AML     1612 12.07        36.9 0.16                           184 298 
 DYA  EE  AML     1612 12.42        20.0 0.19                           184 298 
 MCH  HZ EP       1611 59.18                              30    -1.3 1  275 340 
 MCH  HN ES   3   1612 29.48                              30    -0.9 0  275 340 
 MCH  HE  AML     1612 36.80         4.0 0.30                           275 340 
 MCH  HN  AML     1612 38.79         4.0 0.51                           275 340 


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