DISCLAIMER -- THIS IS NOT AN EARTHQUAKE PREDICTION OR WARNING! The commentary provided with these map(s) is for INFORMATIONAL USE ONLY, and SHOULD NOT be construed as an earthquake prediction, warning, or advisory. Responsibility for such warnings rests with the Office of Emergency Services of the State of California. PLEASE REMEMBER -- THESE ARE PRELIMINARY DATA Releasing these summaries on a timely basis requires that the data, analysis, and interpretations presented are PRELIMINARY. Of necessity they can only reflect the views of the seismologists who prepared them, and DO NOT carry the endorsement of the U.S.G.S. Thus while every effort is made to ensure that the information is accurate, nothing contained in this report is to be construed as and earthquake prediction, warning, advisory, or official policy statement of any kind, of the U.S. Geological Survey, or the U.S. Government. FOR QUESTIONS CONCERNING THIS REPORT Send e-mail to michael@andreas.wr.usgs.gov DO NOT SEND EMAIL TO weekly@garlock.wr.usgs.gov It will not be read. Seismicity Report for Northern California, the Nation, and the World for the week of April 13 - 19, 1995 Data and text prepared by Steve Walter and Barry Hirshorn U.S. Geological Survey 345 Middlefield Rd. MS-977, Menlo Park, CA 94025 Graphics by Quentin Lindh San Francisco Bay Area Yet another quiet week in the Bay Area. During the seven-day period ending at midnight on Wednesday, April 19, 1995 the U.S. Geological Survey office in Menlo Park recorded 20 earthquakes of magnitude one (M1) and greater within the San Francisco Bay area shown in Figure 1. Three of these were as large as M2.0. This total compares to 17 earthquakes during the previous seven-day period (April 6 - 12), two of which were as large as M2. The only earthquake as large as M2 in the central Bay Area was a M2.1 that occurred along early last Thursday morning at the south end of the Concord fault (#1 in figure 1). The epicenter for this event was about three miles northeast of Alamo in much the same location as a pair of M2's that occurred earlier this month. The other two M2 earthquakes occurred in the southern part of the region. The first of these was a M2.0 that occurred last Friday night on the southern Calaveras fault about eleven miles southeast of Morgan Hill (#2/1). The week's largest earthquake occurred Saturday morning on the creeping segment of the San Andreas about 14 miles south of Hollister (#3/1). There were no reports that this M2.7 earthquake was felt. Northern & Central California It was a quiet week throughout the region with no earthquakes as large as M3.0. The Cape Mendocino area saw a trio of M2 offshore events, two along the fracture zone (#2/2) and one in the southern Gorda Plate (#6/2). Activity onshore was limited to a M2.1 about ten miles southeast of Petrolia and a M2.0 about 37 miles northeast of Petrolia (#5/2). Other events of note in the north state include a M2.3 in the northern Sierra Nevada about nine miles north of Truckee (#1/2), a M2.4 about 15 miles northeast of Redding (#7/2), and a M2.0 just east of the Rogers Creek fault about six miles west of Calistoga (#8/2). Central California was even quieter with four M2's on the creeping San Andreas south of Tres Pinos (#4/2) and a M2.5 in the southern Sierra Nevada about 25 miles northeast of Isabella (#3/2). Long Valley Caldera Seismicity increased somewhat within the caldera with eight earthquakes as large as M1.5. Only one was as large as M2, a M2.2 that occurred Sunday morning in the area of the resurgent dome (#2/3). Activity south of the caldera saw a similar increase in activity with a seven events as large as M1.5, including one M2.5 south of Red Slate Mountain (#1/3). USA Seismicity (April 10 - 19) The largest earthquake in the western hemisphere during the week occurred in west Texas, a Mb5.7 that struck Saturday evening in the Glass Mountains area, about 20 miles southeast of the community of Alpine (#2/4). Two people were slightly injured in the quake, which damaged some buildings in the Alpine-Marathon area and produced slight damage as far away as Pecos. The earthquake was felt in much of western and central Texas, as far east as San Antonio and the Dallas-Fort Worth areas and as far west as Roswell, New Mexico. Numerous aftershocks followed including a M3.3 two hours after the mainshock and a M4.0 about a day and a half later. This was the largest earthquake to occur in Texas since August 16, 1931 when a M6.4 struck in the Sierra Vieja Mountains about 50 miles west of Alpine. Other domestic quake of note included a Mb4.1 in northwestern Arizona that was felt at Grand Canyon Village (#5/4) and a Mb3.9 in southeastern South Carolina that was felt in the Charleston area (#6/4). Southern California earthquakes of note included a M3.0 in the Big Bear Lake area (#3/4), a M3.4 Northridge aftershock (#4/4), and a 3.8 south of the border in Baja California, Mexico (#1/4). The Planet Earth (April 10 - 19) The largest earthquake on the planet during the week was a Ms6.3 in the Kuril Islands north of Japan (#4/5). Two other "large" earthquakes also occurred along the western Pacific margin: a Ms6.0 in the Solomon Islands region (#2/5) and a Mb6.0 near the north coast of Irian Jaya (#5/5). Several moderate earthquakes occurred in the mid-ocean including a Ms5.9 along the Atlantic/Antarctic plate boundary (#1/5), a Ms5.4 along the Pacific/Antarctic plate boundary (#6/5), and a Ms5.8 along the northern mid-Atlantic ridge (#3/5). Table 1. Northern & Central California Seismicity (M>1.0) --ORIGIN TIME (UT)-- -LAT N-- --LON W-- DEPTH N N RMS ERH ERZ DUR YR MON DA HRMN SEC DEG MIN DEG MIN KM RD S SEC KM KM REMKS MAG 95 APR 13 705 31.63 36 45.90 121 22.53 3.70 12 2 .45 1.4 2.0 HOL 1.0 95 APR 13 921 25.07 37 54.11 121 58.76 11.71 47 3 .21 .4 .5 CON 1.9 95 APR 13 1121 28.27 39 27.53 120 13.54 11.49 20 2 .19 1.3 3.3 WAK 2.4 95 APR 13 1405 22.91 40 13.78 124 8.64 11.45 14 1 .15 .8 .6 MEN 2.0 95 APR 13 1638 0.39 37 32.73 118 50.51 9.24 21 .08 .5 .7 MOR 1.9 95 APR 13 1947 32.07 37 29.63 118 49.57 1.92 9 .17 2.615.7 MOR-- 1.5 95 APR 13 2220 14.26 35 51.46 120 24.11 5.14 16 2 .04 .3 .5 GOL 1.4 95 APR 13 2223 32.57 36 32.57 121 8.04 8.63 15 .04 .3 .7 PIN 1.4 95 APR 13 2328 59.02 36 24.51 120 59.21 7.77 28 .07 .3 1.0 BIT 2.0 95 APR 13 2332 9.09 40 18.57 124 36.95 11.06 16 1 .15 1.4 .6 MEN- 2.9 95 APR 14 10 22.82 38 11.61 119 23.97 6.10 8 1 .16 1.712.8 WAK - 2.0 95 APR 14 39 49.49 38 47.27 122 46.64 3.32 10 .04 .3 1.3 GEY 1.6 95 APR 14 148 13.06 37 39.26 118 54.02 5.78 17 .10 .3 .7 DOM 1.6 95 APR 14 340 3.20 37 40.60 118 54.15 6.23 7 .02 1.4 1.9 DOM- 1.0 95 APR 14 410 26.88 37 21.29 121 43.08 9.09 10 .05 .4 .8 ALU .9 95 APR 14 457 36.39 36 13.19 120 21.81 11.97 27 1 .08 .2 .4 COA 2.0 95 APR 14 524 20.94 38 47.85 122 46.09 1.39 10 .04 .3 1.3 GEY 1.6 95 APR 14 528 29.65 36 45.32 121 15.78 8.17 17 .05 .3 .6 PAI .8 95 APR 14 628 22.46 37 39.49 118 53.73 4.51 20 .10 .3 .6 DOM 1.5 95 APR 14 708 19.30 36 45.92 121 22.15 8.35 10 1 .18 .8 1.7 HOL 1.0 95 APR 14 729 52.17 37 39.54 118 53.72 4.56 19 .10 .3 .6 DOM 1.5 95 APR 14 815 45.76 37 25.36 121 46.10 4.72 10 1 .08 .4 .7 ALU 1.0 95 APR 14 828 42.31 35 57.90 118 18.38 8.80 15 1 .13 .3 1.4 WWF 2.7 95 APR 14 840 16.95 36 27.41 121 0.27 8.71 20 .07 .3 .9 BIT 1.3 95 APR 14 934 19.69 37 1.07 121 28.65 7.96 24 1 .10 .3 .9 CYS 1.0 95 APR 14 940 52.23 36 23.05 120 57.72 5.77 9 .06 .5 2.5 BIT 1.0 95 APR 14 1217 41.78 37 54.79 118 36.29 9.33 13 2 .15 3.0 2.3 MOL 1.6 95 APR 14 1256 35.12 38 46.19 122 43.96 2.31 14 .07 .3 .5 GEY 1.4 95 APR 14 1315 57.38 37 35.23 118 51.31 9.45 22 .12 .5 .7 MOR 1.7 95 APR 14 1337 6.14 37 37.07 118 53.98 7.66 14 .08 .5 .8 SHE 1.3 95 APR 14 1349 34.04 37 37.53 118 53.97 7.55 11 .06 .6 .8 SMO 1.6 95 APR 14 1349 35.30 37 36.06 118 53.71 6.60 12 .20 1.2 1.0 SHE 1.6 95 APR 14 1710 45.22 38 47.42 122 48.25 4.87 16 .06 .3 .7 GEY 1.7 95 APR 14 1738 20.13 38 48.54 122 45.06 0.21 7 .05 .4 2.2 GEY 1.2 95 APR 14 2036 42.98 38 49.33 122 47.88 5.21 7 1 .02 .4 2.0 GEY 1.2 95 APR 14 2105 53.78 36 38.47 121 15.38 5.51 51 3 .09 .2 .5 STN 2.0 95 APR 14 2207 30.93 35 57.40 118 18.35 1.03 9 2 .16 .7 2.7 WWF 1.6 95 APR 14 2221 1.35 36 38.58 121 15.46 5.69 27 .06 .2 .7 STN 1.5 95 APR 14 2229 31.01 38 47.00 122 46.81 6.67 9 .14 .6 1.7 GEY 1.3 95 APR 14 2357 59.32 38 48.44 122 48.80 3.23 10 .04 .3 1.7 GEY 1.2 95 APR 15 43 18.81 38 46.98 122 45.61 1.87 8 .05 .4 1.4 GEY 1.3 95 APR 15 326 36.09 40 28.05 121 31.27 4.16 11 3 .04 .4 .5 LAS 1.5 95 APR 15 514 33.58 37 26.04 118 53.03 6.99 31 2 .11 .4 1.2 MOR 2.7 95 APR 15 605 29.08 37 3.07 121 29.03 8.89 81 1 .09 .2 .4 CYS 1.9 95 APR 15 748 43.89 36 37.14 121 13.52 5.36 56 2 .08 .2 .5 PIN 2.1 --ORIGIN TIME (UT)-- -LAT N-- --LON W-- DEPTH N N RMS ERH ERZ DUR YR MON DA HRMN SEC DEG MIN DEG MIN KM RD S SEC KM KM REMKS MAG 95 APR 15 845 54.65 40 26.80 124 36.67 15.54 15 1 .12 1.5 .5 MEN 2.6 95 APR 15 1009 39.42 40 18.05 124 18.99 0.70 9 3 .07 .4 .6 MEN 1.4 95 APR 15 1049 52.25 37 37.15 118 50.22 5.54 19 1 .10 .5 .4 HCF 1.3 95 APR 15 1051 30.13 39 56.85 122 45.25 0.04 15 .29 .8 2.9 SAC * 1.8 95 APR 15 1118 35.53 38 50.32 122 49.29 1.04 8 .01 .3 1.0 GEY 1.5 95 APR 15 1143 6.56 36 40.41 121 17.58 3.99 84 5 .11 .1 .3 STN 2.8 95 APR 15 1354 1.00 36 56.56 121 56.13 3.46 35 .11 .4 .7 MON 1.5 95 APR 15 1531 41.00 37 25.73 118 53.23 8.01 17 .06 .5 1.7 SIL 2.0 95 APR 15 1538 58.23 37 26.94 118 52.72 7.75 10 1 .16 2.3 2.4 MOR 1.3 95 APR 15 1622 21.95 38 47.91 122 47.86 0.03 11 .10 .4 1.1 GEY 1.6 95 APR 15 1644 48.87 38 47.87 122 48.11 2.08 16 .11 .3 1.2 GEY 1.5 95 APR 15 1659 39.00 38 50.02 122 49.22 0.03 8 .07 .3 1.6 GEY * 1.4 95 APR 15 1918 30.26 37 37.66 118 51.40 5.53 8 .09 .5 1.0 SMO 1.2 95 APR 15 1929 10.62 38 46.12 122 54.70 5.28 17 .08 .3 .8 GEY 1.4 95 APR 15 2019 56.14 36 35.23 121 11.19 2.42 12 .04 .3 .4 PIN 1.5 95 APR 16 5 20.39 40 26.54 123 36.49 23.51 14 .13 .5 .9 EUR 2.0 95 APR 16 34 6.06 38 49.88 122 48.33 1.51 8 .02 .3 1.4 GEY 1.2 95 APR 16 408 21.99 38 50.49 119 47.39 0.00 8 3 .09 1.3 1.6 WAK * 2.0 95 APR 16 441 45.75 37 39.63 118 50.85 1.51 12 .05 .3 .4 HCF 1.5 95 APR 16 819 19.62 37 26.20 118 48.39 9.25 10 .05 1.1 2.0 MOR 1.0 95 APR 16 958 47.19 36 43.81 120 48.97 1.77 9 .07 1.2 9.6 ORT - 2.6 95 APR 16 1049 9.73 37 25.72 118 52.99 7.92 21 1 .11 .6 1.5 SIL 1.9 95 APR 16 1056 43.24 36 43.74 120 48.33 0.98 17 .09 1.1 8.3 ORT-- 1.4 95 APR 16 1513 6.48 37 40.88 118 50.34 3.07 10 .02 .4 .7 DOM 1.2 95 APR 16 1516 54.41 37 40.53 118 50.38 2.64 10 .07 .3 .8 DOM 1.5 95 APR 16 1524 10.43 37 40.57 118 50.66 3.98 21 .12 .4 .6 DOM 2.2 95 APR 16 1526 40.43 37 40.53 118 50.37 3.37 14 .09 .4 .7 DOM 1.4 95 APR 16 1534 3.90 37 40.64 118 50.39 3.02 8 .07 .4 .9 DOM 1.6 95 APR 16 1538 22.19 37 40.53 118 50.42 3.10 12 .07 .3 .7 DOM 1.6 95 APR 16 1608 33.90 37 40.62 118 50.64 4.06 28 2 .13 .3 .5 DOM 2.0 95 APR 16 1932 15.32 37 33.15 118 48.71 7.13 10 .09 1.0 1.9 MOR 1.1 95 APR 16 2007 37.79 39 3.54 123 3.70 0.16 9 2 .11 .4 1.3 MAA- 1.4 95 APR 17 242 35.08 38 49.47 122 47.82 5.25 29 .09 .2 .6 GEY 2.2 95 APR 17 258 31.10 37 32.43 118 50.63 10.17 8 .04 .9 1.4 MOR 1.3 95 APR 17 419 39.83 38 47.55 122 44.56 2.08 25 .07 .2 .5 GEY 1.9 95 APR 17 548 12.65 40 49.37 125 28.07 21.96 16 2 .12 4.710.2 DEL - 2.8 95 APR 17 718 54.55 38 56.19 122 36.60 4.43 8 .09 .5 1.4 BAR 1.3 95 APR 17 944 51.84 39 15.52 122 55.24 3.55 10 .08 .4 4.0 BAR 1.6 95 APR 17 956 48.93 39 35.74 121 51.50 23.86 16 3 .11 .5 .9 SAC 1.6 95 APR 17 1411 7.87 38 49.49 122 46.58 3.62 30 .12 .3 .9 GEY 2.1 95 APR 17 1538 9.99 38 3.98 120 24.56 0.99 8 1 .07 .3 6.5 YOS * 1.5 95 APR 17 1725 34.79 38 48.45 122 53.62 6.40 9 .04 .5 .7 GEY 1.5 95 APR 17 1747 28.81 36 59.15 121 38.08 2.69 27 .15 .3 1.0 SAR 1.7 95 APR 17 1838 10.62 36 59.57 121 44.37 13.72 17 .06 .4 .9 SAR 1.1 95 APR 17 1841 57.32 38 49.21 122 47.94 2.61 8 .08 .4 2.6 GEY 1.2 --ORIGIN TIME (UT)-- -LAT N-- --LON W-- DEPTH N N RMS ERH ERZ DUR YR MON DA HRMN SEC DEG MIN DEG MIN KM RD S SEC KM KM REMKS MAG 95 APR 17 2043 29.79 38 49.03 122 48.72 6.36 7 .07 .5 3.3 GEY 1.4 95 APR 17 2206 0.59 37 35.68 118 50.27 11.65 19 .10 .4 .6 MOR 2.0 95 APR 17 2325 43.75 38 49.48 122 48.68 3.31 8 .03 .3 2.9 GEY 1.0 95 APR 18 255 13.58 36 32.10 121 7.52 8.01 10 .02 .4 .9 PIN .9 95 APR 18 312 47.26 36 38.67 121 15.75 8.80 25 .04 .2 .5 STN 1.4 95 APR 18 317 46.43 36 31.91 121 7.38 8.80 14 .05 .3 .8 PIN 1.0 95 APR 18 431 45.00 36 55.11 121 24.95 6.84 14 .05 .3 1.2 HOL .9 95 APR 18 435 17.61 38 49.28 122 47.93 3.51 7 .02 .3 3.2 GEY 1.2 95 APR 18 620 52.19 38 49.90 122 57.35 2.65 10 .03 .5 .7 GEY 1.3 95 APR 18 820 57.64 36 2.59 120 35.71 0.05 12 .13 .7 2.1 SLA * 1.7 95 APR 18 1146 48.74 37 18.04 121 40.37 5.75 14 .04 .3 .7 SFL 1.4 95 APR 18 1208 42.01 37 18.02 121 40.38 5.64 41 .07 .2 .5 SFL 1.9 95 APR 18 1220 47.56 36 40.56 121 17.53 5.46 19 .18 .5 1.1 STN 1.8 95 APR 18 1326 52.39 40 50.25 121 51.50 21.40 8 .06 1.1 1.4 SHA 2.4 95 APR 18 1434 24.40 36 31.19 121 5.95 9.58 28 .12 .3 .7 PIN 2.0 95 APR 18 1652 22.40 37 39.27 119 1.32 2.84 10 .08 .5 1.5 MAM 1.6 95 APR 18 1821 18.36 38 49.50 122 50.05 0.40 8 .06 .3 1.5 GEY 1.2 95 APR 18 2139 51.53 36 46.08 121 28.54 8.37 30 2 .18 .4 .6 SJB 1.6 95 APR 19 33 39.77 38 49.01 122 47.57 0.06 13 .09 .3 1.3 GEY * 1.8 95 APR 19 48 57.54 37 45.93 121 56.58 6.82 13 2 .12 .3 1.5 DAN 1.2 95 APR 19 100 37.61 38 47.60 122 46.93 1.80 14 .12 .3 1.3 GEY 1.7 95 APR 19 213 32.53 38 49.97 122 52.70 3.46 12 .06 .4 1.4 GEY 1.5 95 APR 19 341 41.91 38 46.93 122 45.67 1.60 7 .07 .4 1.6 GEY 1.1 95 APR 19 642 35.56 36 28.16 121 2.91 6.67 16 2 .06 .3 .7 BIT 1.1 95 APR 19 804 28.17 36 57.81 121 36.22 3.74 23 .13 .3 .7 SAR 1.2 95 APR 19 834 31.39 38 48.45 122 46.82 1.39 14 .09 .3 1.2 GEY 1.9 95 APR 19 859 9.37 36 33.30 121 3.27 8.72 36 2 .11 .3 .6 BVL 2.2 95 APR 19 953 37.18 40 53.23 122 31.24 14.35 8 1 .09 .5 2.8 SHA 1.6 95 APR 19 953 42.87 37 32.27 118 51.18 11.24 15 1 .12 .5 .9 MOR 1.3 95 APR 19 1743 0.99 38 47.18 122 46.23 2.29 17 .08 .2 1.0 GEY 2.0 95 APR 19 2007 20.03 37 2.26 121 8.65 0.89 24 .13 .7 9.7 ORT - 1.6 95 APR 19 2328 48.20 38 49.42 122 47.83 7.24 7 .07 .5 1.3 GEY 1.1 95 APR 20 100 42.94 37 28.40 121 48.92 7.03 7 .07 .6 1.1 MIS 1.1 95 APR 20 228 54.48 37 27.70 118 34.86 15.45 10 .07 .6 2.2 RVL 1.5 95 APR 20 453 13.43 36 33.04 121 8.48 4.27 20 .09 .3 1.0 PIN 1.8 95 APR 20 516 52.54 38 46.26 122 54.60 5.60 22 .09 .3 .8 GEY 2.3 95 APR 20 522 34.88 38 35.82 122 41.48 2.04 22 .14 .3 1.4 NAP 2.0 TABLE 2. Data from National Earthquake Information Center (NEIC) UTC TIME LAT LONG DEP GS MAGS SD STA REGION AND COMMENTS HRMNSEC MB Msz USED ------------------------------------------------------------------------------ APR 10 005454.4* 43.242N 127.042W 10G 0.5 42 OFF COAST OF OREGON 031114.7 30.389N 130.693E 33N 5.1 4.8 0.9 77 KYUSHU, JAPAN. Felt (III JMA) at Aburatsu. 033657.3* 51.410N 15.793E 10G 0.7 8 POLAND. ML 3.7 (GRF). 050234.1 33.196N 115.648W 10G 0.5 17 SOUTHERN CALIFORNIA. ML 2.8 095112.6* 21.715N 121.204E 33N 4.5 0.8 16 TAIWAN REGION 144454.8* 42.004N 126.175W 10G 0.5 40 OFF COAST OF OREGON 184344.8% 34.101S 70.722W 90G 0.1 10 CHILE-ARGENTINA BORDER REGION 192547.3 35.734N 69.528E 100G 4.6 0.7 38 HINDU KUSH REGION, AFGHANISTAN 210140.0* 17.890S 178.343W 500G 4.6 0.9 13 FIJI ISLANDS REGION 230417.7* 27.173S 176.628W 33N 4.5 0.8 12 KERMADEC ISLANDS REGION APR 11 062328.0& 58.940N 154.440W 121 2.9 32 ALASKA PENINSULA. . 062626.2? 33.79 S 72.08 W 10G 0.5 9 OFF COAST-CENTRAL CHILE. MD 3.5 105946.8? 4.37 S 134.66 E 33N 4.3 1.6 7 IRIAN JAYA REGION, INDONESIA 132028.1* 35.876N 8.409W 10G 3.5 1.2 46 WEST OF GIBRALTAR. mbLg 4.1 134604.6? 18.88 S 169.42 E 200G 4.5 1.2 15 VANUATU ISLANDS 145526.1% 33.804S 70.782W 80G 0.2 10 CHILE-ARGENTINA BORDER REG. 150510.3? 7.66 S 73.94 W 33N 4.8 0.9 11 PERU-BRAZIL BORDER REG. 163412.1? 34.96 S 70.99 W 100G 0.2 10 CHILE-ARGENTINA BORDER MD 3.1 183409.9* 48.243N 153.268E 33N 4.6 0.4 32 KURIL ISLANDS 193058.0* 31.797N 116.015W 10G 0.7 24 BAJA CALIFORNIA, MEXICO. ML 3.8 202950.1? 37.17 N 135.95 E 402? 4.2 0.7 25 SEA OF JAPAN 213308.0* 27.816S 176.966W 33N 5.1 5.3 1.1 35 KERMADEC ISLANDS REGION APR 12 023913.1? 40.30 N 143.37 E 33N 4.4 0.9 11 OFF EAST COAST OF HONSHU, JAPAN 050428.1% 33.305S 71.930W 20G 0.3 11 NEAR COAST-CENTRAL CHILE. MD 3.8 052114.5% 33.302S 71.949W 20G 0.4 11 NEAR COAST-CENTRAL CHILE. MD 4.3 052307.0* 36.339N 140.516E 76* 4.8 0.9 33 NEAR EAST COAST OF HONSHU, JAPAN 080443.8? 1.91 N 127.12 E 121* 5.0 0.3 11 HALMAHERA, INDONESIA 100128.2% 32.692S 71.567W 10G 0.6 11 NEAR COAST-CENTRAL CHILE. MD 3.9 104335.5% 33.301S 71.931W 20G 0.3 11 NEAR COAST-CENTRAL CHILE. MD 3.8 110744.6* 53.816N 163.611W 33N 3.9 1.3 16 UNIMAK ISLAND REGION. ML 4.1 114842.1? 34.49 S 71.26 W 60G 0.2 11 NEAR COAST-CENTRAL CHILE. MD 3.6 132744.6? 15.23 S 173.56 W 33N 4.7 0.8 10 TONGA ISLANDS 142137.4 62.746N 150.712W 33N 0.7 12 CENTRAL ALASKA. ML 2.9 (PMR). 164453.4 59.723N 153.020W 150G 0.8 15 SOUTHERN ALASKA 182232.5 2.665N 78.330W 43 5.2 0.9 73 NEAR WEST COAST OF COLOMBIA 202904.5 65.030N 149.261W 10G 0.9 30 NORTHERN ALASKA. ML 3.6 (PMR). APR 13 001957.4? 32.38 S 69.93 W 130G 0.3 10 MENDOZA PROV., ARGENTINA. MD 2.7 025910.3* 13.379S 170.525E 600G 4.5 0.8 42 VANUATU ISLANDS REGION 034438.0& 60.870N 147.080W 3 48 SOUTHERN ALASKA. . ML 2.6 035009.6& 61.280N 152.030W 100 96 SOUTHERN ALASKA. . 041608.2* 0.558S 124.290E 33N 5.1 5.2 1.2 22 SOUTHERN MOLUCCA SEA 114136.3* 17.888S 178.749W 600G 4.6 0.6 35 FIJI ISLANDS REGION 125146.0? 34.49 S 70.40 W 10G 0.3 8 CHILE-ARGENTINA BORDER REG. 132602.0 35.426N 119.710W 5G 0.9 18 CENTRAL CALIFORNIA. ML 3.1 (GS). 145825.0* 33.941S 70.219W 10G 1.3 10 CHILE-ARGENTINA BORDER REG. 150028.3 5.467N 79.794W 10G 5.1 4.4 0.8 47 SOUTH OF PANAMA 174143.1? 9.62 S 105.97 E 33N 4.9 1.5 9 SOUTH OF JAWA, INDONESIA 175712.7? 20.79 S 174.43 W 33N 4.6 0.7 5 TONGA ISLANDS 202320.0* 37.484N 36.122E 33N 4.8 0.8 20 TURKEY 234353.6 43.722N 147.320E 54* 5.3 4.6 0.9 70 KURIL ISLANDS APR 14 003253.8 30.209N 103.327W 5G 5.7 5.4 1.0 121 WESTERN TEXAS. Mw 5.7 (GS), 5.8 (HRV). Two people were slightly injured in Brewster County. Some damage occurred in the Alpine-Marathon area. Slight damage occurred at Ozona and in the Pecos area. Felt in much of western and central Texas as far east as San Antonio and the Dallas-Fort Worth area. Felt in southeastern New Mexico as far west as Roswell. 011146.9& 30.250N 103.300W 5G 2 WESTERN TEXAS. . mbLg 2.7 021424.4& 30.250N 103.300W 5G 2 WESTERN TEXAS. . mbLg 2.8 021936.8& 30.250N 103.300W 5G 3 WESTERN TEXAS. . mbLg 3.3 034841.5& 30.250N 103.300W 5G 2 WESTERN TEXAS. . mbLg 2.6 055338.5& 30.250N 103.300W 5G 2 WESTERN TEXAS. . mbLg 2.7 060112.0? 17.08 N 98.87 W 33N 4.5 1.2 20 GUERRERO, MEXICO. Felt at Iguala and Chilpancingo. Felt lightly at Mexico City. 082711.8& 30.250N 103.300W 5G 2 WESTERN TEXAS. . mbLg 2.8 100257.4& 30.250N 103.300W 5G 3 WESTERN TEXAS. . mbLg 2.9 131516.6* 60.576S 19.985W 10G 5.7 5.9 1.1 9 SOUTHWESTERN ATLANTIC OCEAN. 141259.6 1.801S 77.458W 165D 5.4 0.7 88 ECUADOR 182825.5 34.199N 116.770W 10G 0.8 26 SOUTHERN CALIFORNIA. ML 3.0 APR 15 053630.6 43.902N 147.294E 33N 5.5 4.7 0.5 80 KURIL ISLANDS 065405.8% 33.826S 70.930W 70G 0.2 6 CHILE-ARGENTINA BORDER REG. 111039.9% 33.511S 71.950W 20G 0.4 11 NEAR COAST-CENTRAL CHILE. MD 4.1 114306.4 36.645N 121.312W 5G 0.7 44 CENTRAL CALIFORNIA. ML 2.8 (GS). 125841.3% 33.858S 70.716W 80G 0.2 11 CHILE-ARGENTINA BORDER. MD 3.4 133318.8? 52.50 N 172.65 E 33N 4.2 1.0 8 NEAR ISLANDS, ALEUTIAN ISLANDS 143328.8 30.263N 103.278W 5G 0.7 7 WESTERN TEXAS. mbLg 4.0 (GS). Felt in the Alpine area and at Fort Davis. 201759.6* 13.963N 90.338W 33N 4.4 0.8 15 NEAR COAST OF GUATEMALA 220045.3 34.322N 118.525W 5G 0.7 55 SOUTHERN CALIFORNIA. ML 3.4 APR 16 030312.4? 33.99 S 72.01 W 10G 0.7 9 OFF COAST-CENTRAL CHILE. MD 3.5 083917.7* 16.881N 46.468W 10G 4.6 4.4 0.9 24 NORTHERN MID-ATLANTIC RIDGE 090002.0? 20.31 S 177.82 W 500G 4.5 1.2 6 FIJI ISLANDS REGION 102625.3& 30.250N 103.300W 5G 2 WESTERN TEXAS. . mbLg 2.5 114948.5? 32.44 S 70.58 W 10G 0.5 10 CHILE-ARGENTINA BORDER. MD 3.8 132349.3 9.670S 159.391E 33N 5.5 5.7 0.9 53 SOLOMON ISLANDS. Mw 5.8 (GS), 203609.5* 20.895S 174.254W 33N 4.9 0.8 20 TONGA ISLANDS APR 17 011419.8 8.462S 156.460E 33N 5.8 6.0 0.8 50 SOLOMON ISLANDS. Mw 6.1 (GS), 051844.3 60.293N 153.055W 128 4.4 1.1 25 SOUTHERN ALASKA. Felt (II) at Anchorage. 071434.7 33.744N 38.520W 10G 5.6 5.8 0.8 85 NOR. MID-ATLANTIC RIDGE. Mw 6.1 082346.0 35.943N 112.218W 5G 4.2 0.5 33 WESTERN ARIZONA. ML 4.1 (GS). Felt at Grand Canyon Village. 084959.7& 30.250N 103.300W 5G 1 WESTERN TEXAS. . mbLg 2.5 120227.6? 10.94 N 86.52 W 33N 4.9 1.1 30 OFF COAST OF COSTA RICA 134556.0* 32.915N 79.964W 5G 0.8 8 SOUTH CAROLINA. mbLg 3.9 (GS). Felt in the Charleston area. 164815.8* 20.131S 178.825W 600G 4.6 1.0 16 FIJI ISLANDS REGION 232808.4 45.955N 151.281E 33N 6.1 6.3 0.7 154 KURIL ISLANDS. Mw 6.8 APR 18 034938.8 2.131S 140.498E 33N 6.0 5.8 0.8 38 NEAR NORTH COAST OF IRIAN JAYA. 052358.1 45.741N 151.422E 33N 5.8 5.0 0.7 117 KURIL ISLANDS. Mw 5.7 (HRV). 095636.4 66.741N 155.386W 5G 4.5 0.9 22 NORTHERN ALASKA 112627.2? 34.38 N 139.79 E 33N 4.9 1.0 12 NEAR S. COAST OF HONSHU, JAPAN. Felt (IV JMA) at Odawara and Shizuoka; (III JMA) at Ajiro. 162335.6* 54.291S 136.671W 10G 5.3 5.4 1.0 16 PACIFIC-ANTARCTIC RIDGE APR 19 035004 Q 43.9 N 148.1 E 33N 5.9 0.6 115 EAST OF KURIL ISLANDS Note: Computer users can get faster acces to the Weekly Seismicity Reports in any of three ways: 1. World-Wide-Web (WWW) access: http://quake.wr.usgs.gov 2. Anonymous FTP access: quake.wr.usgs.gov (in pub/www/QUAKES/WEEKREPS) 3. Email Access: (send email to michael@andreas.wr.usgs.gov) Notes for Table 1: Origin time in the list is in GMT, in the text and on maps it is in local time. N RD: is the number of readings used to locate the event. N S: is the number of S waves in N RD. RMS SEC: is the root mean squared residual misfit for the location is seconds, the lower the better, over 0.3 to 0.5 seconds is getting bad, but this is machine, not hand timed, data. ERH: is the estimated horizontal error in kilometers. ERZ: is the estimated vertical error in kilometers. N FM: is the number of readings used to compute the magnitude. REMKS: obtuse region codes that denote the velocity model used to locate the event. DUR MAG: is the magnitude as determined from the duration of the seismograms, not the amplitude. Sort of like going to echo canyon and measuring how loud your yell is by counting echos. FIG: denotes the figure/event number in the maps posted separately.