Information message about the strong earthquake in the area of Rat Islands, June 23, 2014.

     The strong earthquake M=7.3 has occurred on June 23, 2014 at 20:53 GMT (June 24, 00:53 Moscow time) in the area of Rat Islands, Aleutian Islands.
     Parameters of the earthquake have been determined in the Alert Service (AS) of Information Processing Center (IPC) of Geophysical Survey of RAS in Obninsk with station data obtained from digital and analog seismic stations of Russia, countries of CIS and from abroad. Alert message on this earthquake has been delivered in 15 min after registration to the Ministry of Emergency of the Russian Federation (EMERCOM).
     Preliminary processing has been done with data from 59 stations, accurate processing - with data 68 stations.
     Fig. 1 presents fragments of records obtained from digital stations Bilibino (∆ 17.4º), Yuzhno-Sakhalinsk (∆ 23.8º), Tiksi (∆ 29.5º), Kuldur (∆ 29.6º), Mys Shultsa (∆ 33.1º). Fig. 2 presents fragments of records obtained from digital stations Lovozero (∆ 57.7º), Arti (∆ 61.4º), Kirov (∆ 62.5º), Pulkovo (∆ 65.9º), Obninsk (∆ 68.9º).

Figure 1
 

Figure 2
 
     IPC GS RAS also has obtained information with parameters of this event from some seismological centers, these data are given in table 1:
Table 1
NN Time in origin h-min-s (GMT) Lat degr. Lon degr. Depth km N s/st Ms/ N mb/ N I0 calc GAP Center
1 20-53-07.4 51.84 178.81  100  68  7.3/357.3/366.5-7 56 IPC GS RAS (Accurate)
2 20-53-07.3 51.8 178.8  100  59  7.2/247/266.5-7 56 IPC GS RAS (Preliminary)
3 20-53-09.0 51.855 178.746  100  493  Mw 7.9   46 CSEM
4 20-53-10.0 51.797 178.76  107.49  123  Mw 7.9   24 NEIC
  • IPC GS RAS - Informational Processing Center, Geophysical Survey, Russian Academy of Sciences
  • CSEM - European - Mediterranean seismological center
  • NEIC - National Earthquakes Information Center of US Geological Service
    • Epicenter
         Fig. 3 presents epicenter of this earthquake with red star, its origin was located in the area of Rat Islands, Aleutian Islands, USA, at the depth of 100 km, 817 km E-S-E of Preobrazhenskoe, Russia, and 851 km W of Nikolski, USA.

    Figure 3
    Aftershock
         GS RAS registered 13 aftershocks with М>=4.6 within 12 hours after the main shock.
    N Date   &   Time (GMT)
    yy-mm-dd hh:mm:sec    		 Lat
    degr.    		 Lon
    degr.    		 Depth
    km    		 N
    station    		 Ms/ N mb/ N Io
    calc.    		 Region
    201423322014-06-23 21:11:37.051.91178.6910043-6.2/ 334.5-5 Rat Islands, Aleutian Islands
    201423332014-06-23 21:30:46.052.12178.2410041-6.1/ 274.5 Rat Islands, Aleutian Islands
    201423342014-06-23 22:03:24.052178.6210027-5.0/ 14-Rat Islands, Aleutian Islands
    201423372014-06-23 22:47:49.052.01178.5510024-4.8/ 13-Rat Islands, Aleutian Islands
    201423382014-06-23 22:29:49.052.02178.6510043-6.1/ 324.5 Rat Islands, Aleutian Islands
    201423392014-06-23 23:33:50.051.83178.2410018-4.7/ 15-Rat Islands, Aleutian Islands
    201423402014-06-23 23:39:29.052.02178.5710020-4.6/ 11-Rat Islands, Aleutian Islands
    201423432014-06-24 00:52:26.051.99178.4510064-5.6/ 333-3.5 Rat Islands, Aleutian Islands
    201423442014-06-24 03:15:38.052.18176.7133696.4/ 376.4/ 327-7.5 Rat Islands, Aleutian Islands
    201423622014-06-24 04:39:05.052.1176.621028-4.9/ 195-5.5 Rat Islands, Aleutian Islands
    201423452014-06-24 06:20:18.052.07178.510050-5.2/ 262-2.5 Rat Islands, Aleutian Islands
    201423472014-06-24 06:55:27.052178.5110044-5.0/ 25-Rat Islands, Aleutian Islands
    201423482014-06-24 08:12:33.052.26176.453350-5.5/ 344.5-5 Rat Islands, Aleutian Islands
    Macroseismic manifestations
         According to ITAR-TASS tsunami alert was announced by Pacific Center of tsunami warnings for the coast lines of Aleutian Islands from Nikolski Island to Attu Island. Preventive evacuation of residents from the shore areas has bee started in towns St Paul, St George, Adak and Atka of Aleutian Islands. According to GS RAS this earthquake was felt in Severo-Kurilsk and Petropavlovsk-Kamchatsky with intensity 2.
    Focal mechanism and seismic moment of the earthquake
         Focal mechanism was obtained in IPC GS RAS with signs of initial arrivals of P waves at 129 stations, including 84 stations which registered the waves of compression (plus signs) and 45 stations which registered tension waves (minus signs). All these stations are located in the inerval of epicental distances of 0–98º and are dispersed uniformly along the azimuths. Focal mechanism of the origin in stereographic projection at the lower hemisphere is presented in fig. 4, elements of mechanism are presented in table.2. Fig. 5, 6 present mechanisms of the origin obtained by USGS NEIC with tensor moment technique and use of long period spatial waves (Mww) and in Quick CMT Catalog, USA with CMT technique. Both solutions are close. This earthquake has occurred under the action of close in value N-E oriented tensile stresses and compressing stresses oriented to the south. Nodal plane NP1 is flat (DP=26–30º), it strikes S-W (STK=204-210º). Nodal plane NP2 is steeply dipping (DP=84–86º), it strikes N-W (STK=304-308º). The type of motion along the flat plane – left lateral fault, along the steeply dipping plane – normal fault. According to USGS NEIC – Mo=9.23*10**20 N*m, Mw=7.9, according to Quick CMT Mo=9.96*10**20 N*m, Mw=7.9
    Table 2
    Axes of main strengths Nodal planes Center
    T P N NP1 NP2
    Pl Azm Pl Azm Pl Azm Stk Dp Slip Stk Dp Slip
    335843185 2930720430-11304 84-119IPC GS RAS
    356142191 2831021029-9307 86-118NEIC
    346045193 2531120726-13308 84-115Quick CMT
  • IPC GS RAS - Informational Processing Center, Geophysical Survey, Russian Academy of Sciences
  • NEIC - National Earthquakes Information Center of US Geological Service
  • Quick CMT - Quick CMT catalog

    • Figure 4
    Figure 5

    Figure 6


    News | Catalogs | Wave Forms | Alert Service | Software | Links | Srtucture | Publications | Conferences | Announce | About
    © FRC GS RAS 1993-2018