^ _ £ ¤ 71 £ ¤ 71 £ ¤ 64 £ ¤ 71 £ ¤ 71 £ ¤ 270 £ ¤ 70 £ ¤ 70 £ ¤ 278 £ ¤ 371 £ ¤ 71 £ ¤ 371 £ ¤ 79 £ ¤ 79 £ ¤ 278 £ ¤ 70 £ ¤ 270 £ ¤ 270 £ ¤ 62 £ ¤ 63 £ ¤ 167 £ ¤ 49 £ ¤ 49 £ ¤ 63 £ ¤ 165 APPROXIMATE LIMIT OF FELT AREA § ¨ ¦ 40 § ¨ ¦ 40 § ¨ ¦ 530 § ¨ ¦ 30 § ¨ ¦ 540 § ¨ ¦ 55 § ¨ ¦ 430 § ¨ ¦ 540 § ¨ ¦ 630 Ï U V 25 Ï U V 310 £ ¤ 71 £ ¤ 70 £ ¤ 67 £ ¤ 64 £ ¤ 167 £ ¤ 79 £ ¤ 62 £ ¤ 270 £ ¤ 49 £ ¤ 165 £ ¤ 65 £ ¤ 82 £ ¤ 412 £ ¤ 425 £ ¤ 278 £ ¤ 63 £ ¤ 371 £ ¤ 271 £ ¤ 371 £ ¤ 62 £ ¤ 63 £ ¤ 63 £ ¤ 62 £ ¤ 63 £ ¤ 62 £ ¤ 167 £ ¤ 412 £ ¤ 79 £ ¤ 67 £ ¤ 79 £ ¤ 82 £ ¤ 82 £ ¤ 412 £ ¤ 79 £ ¤ 63 £ ¤ 62 £ ¤ 165 £ ¤ 425 £ ¤ 65 £ ¤ 65 £ ¤ 64 £ ¤ 79 £ ¤ 278 £ ¤ 63 Little Rock Jonesboro Fort Smith Rogers Conway Fayetteville Pine Bluff Bella Vista Texarkana Springdale Paragould Searcy Russellville Highfill Hope Gilmore Beebe Lowell Keo Ozark Tull North Little Rock Cabot Hot Springs Benton Bentonville Bryant Marion Hot Springs Village West Memphis Camden Blytheville Tontitown Clarksville Jacksonville Newport El Dorado Clinton East End Barling Goshen Pottsville Van Buren Sherwood Forrest City Fairfield Bay Diaz Centerton Guy Wynne Cherokee Village Maumelle Harrison Mena Batesville Clarkedale Alma Grannis Magnolia South Bend Walnut Ridge Monticello Osceola Vilonia Malvern Paris Oxford Highland Warren Atkins Horseshoe Bend Cedarville Morrilton Ward Glenwood Holland Mulberry Hardy Fordyce Greenwood Prescott Etowah Bay Ashdown Kibler Stuttgart Piggott Pea Ridge Turrell Melbourne Gateway Siloam Springs Greenbrier Brinkley Crossett Hoxie Lamar Mountain Home Helena-West Helena Little Flock Pocahontas White Hall Ash Flat Carlisle McGehee Lonoke Berryville Rose Bud Earle Prairie Grove Haskell Arkadelphia De Queen Elkins Greers Ferry Heber Springs Rosston Amity Chidester Dyer Hazen Ola Danville Traskwood Trumann Perryville Farmington Manila Waldron Lafe Lake View Gravette Salesville Dover Holiday Island Star City Ozark Acres Corning Mountain View Marked Tree Gentry Rison Midway Nashville Eureka Springs Johnson Bald Knob London Bull Shoals Dumas Sheridan Dermott Stamps Cushman Eudora Corinth Decatur Cave Springs Rockport Branch Salem Smackover Parkin Cotter Bodcaw Lost Bridge Village Gassville Caldwell Booneville DeWitt Lynn Twin Groves Concord Altus Marianna Redfield Hamburg Waldo Shirley West Fork Charleston Hector Vandervoort Huntsville Knoxville Bauxite Palestine Oppelo Dardanelle Cove Wheatley Wooster Gurdon Yellville Mayflower Wickes Hampton Colt Judsonia Avoca Lavaca Garfield Ben Lomond Norfork Coal Hill Sidney Viola Grady Lockesburg Reader Elm Springs Hughes Stephens DesArc Black Rock Madison Calico Rock Greenland Prairie Creek Menifee Little Rock Air Force Base Bono Marshall Cave City Lincoln Fountain Lake Dierks Flippin Jennette Ratcliff Daisy Oak Grove Caraway Enola Fifty-Six Gould Augusta Edmondson Wilmot Kensett Lake City Bluff City Strong Pindall Cale Diamondhead Horatio Franklin Subiaco Norphlet Mansfield Dell Lewisville Foreman Ravenden Briarcliff Wiederkehr Village Mount Pleasant Casa Portia Fouke England Austin Newark Winslow Mc Crory Pineville Harrisburg Altheimer Strawberry Wilmar Hartford Alexander Gosnell Belleville Quitman Thornton Leachville Caddo Valley Emmet Rector Magnet Cove Lake Village Weiner Diamond City Marvell Moro Lepanto Central City Alpena Tuckerman McNeil Bethel Grove Calion Wrightsville Magazine Hartman Coy Tyronza Damascus Hatfield Green Forest Blevins Zinc Hackett Wilton Willisville Shannon Hills Wedington Reyno Prattsville Dyess Wilson Gillett Bonanza Austin Oak Grove Heights Taylor Murfreesboro Rondo Felsenthal Oden Clarendon Mount Ida Plainview OKean Tillar Adona Biscoe Summit Bergman Norman Huttig Biggers Buckner Big Flat Leola Bearden Tollette Leslie Perla Denning Luxora Sparkman Caulksville Perrytown Mineral Springs Maynard Monette Garner Portland Humphrey Houston Bradley Patterson Parkdale Bigelow Mountain Pine Perry Beedeville Gillham Evening Shade Datto Lakeview Winthrop Kingsland Moorefield Carthage Brookland St. Joe Garland Imboden Delaplaine Bradford Campbell Station Plumerville Okolona DeVallsBluff Mountainburg Guion Marmaduke Lexa Hunter Holly Grove Sulphur Rock Burdette Higginson Fargo Washington Elaine Junction City Cotton Plant St. Charles Harrell Morrison Bluff Delight McCaskill Alicia McRae Grubbs Cave Springs Jasper Western Grove Blue Mountain Mammoth Springs Mount Vernon Peach Orchard Bellefonte Minturn Antoine Swifton Widener Smithville Friendship Magness Ozan Knobel Ravenden Springs Havana Everton Lead Hill Ulm Tinsman Sulphur Springs Keiser Chester Ogden Banks Egypt Letona St. Paul Cherry Valley Pangburn Donaldson Scranton Gilbert Omaha Cash Almyra Pleasant Plains Lonsdale Griffithville Roe Aubrey Springtown Hickory Ridge McNab Sedgwick Joiner Winchester Midland Jericho Fountain Hill Pollard Victoria Tupelo West Point Black Oak East Camden Fisher Williford Montrose Crawfordsville McDougal Hindsville Sunset College City Arkansas City Haynes Weldon Valley Springs Bassett St. Francis Allport Louann Fulton Gum Springs Wabbaseka Russell Jackson-Port Success Black Springs Nimmons Watson Greenway Marie Fourche Georgetown Reed Birdsong Oil Trough Sherrill Cammack Village Powhatan Patmos La Grange Whelen Springs Jerome Rudy Summers Waldenburg Amagon South Lead Hill Horseshoe Lake Mitchellville Cane Hill Anthonyville Evansville Salem Springs Oakhaven Cincinnatti Morrow Dutch Mills Litteral Durham Sulphur City £ ¤ 71 £ ¤ 70 £ ¤ 67 £ ¤ 64 £ ¤ 167 £ ¤ 61 £ ¤ 79 £ ¤ 270 £ ¤ 49 £ ¤ 165 £ ¤ 65 £ ¤ 82 £ ¤ 278 £ ¤ 63 £ ¤ 79 £ ¤ 63 Ï U V 36 Ï U V 225 Ï U V 25 Ï U V 287 Ï U V 365 Ï U V 107 Ï U V 89 Ï U V 285 Ï U V 60 Ï U V 124 Ï U V 286 Ï U V 319 Ï U V 107 Ï U V 285 Ï U V 319 Modified Mercalli Intensities Enola Earthquake Swarm Seismic Event: Magnitude 4.5 20 January 1982 @ 6:33 PM CST ( N GH-EQ-MMI-AR-0001 10 0 10 20 30 40 50 60 5 Miles 10 0 10 20 30 40 50 60 5 Kilometers Arkansas Geological Survey Bekki White, Director and State Geologist Symbols ^ _ Earthquake Epicenter Interstates US Highways State Highways Incorporated Areas ¡ ¢ 62 § ¨ ¦ 40 Æ · 225 Although this map was compiled from digital data that was successfully processed on a computer system using ESRI ArcGIS 9.x software at the Arkansas Geological Survey (AGS), no warranty, expressed or implied, is made by the AGS regarding the unity of the data on any other system, nor shall the act of distribution constitute any such warranty. The AGS does not guarantee this map or digital data to be free of errors or liability for interpretations from this map or digital data, or decisions based thereof. 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 Arkansas Geological Survey. The Feature Class Data used in the making of this map was acquired at the GeoStor online. Disclaimer Light None None None Weak None I II IV Moderate V Strong Light VI Very Strong Moderate VII Moderate Heavy Severe VIII Extreme X+ Violent Heavy IX Weak None III Very Light Very Heavy 1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7+ INTENSITY SHAKING DAMAGE MAGNITUDE By Scott M. Ausbrooks and Erica Doerr 2009 1 : 850,000 Jerry W. Clark Date: Scale: Digital Compilation: 20 February 2009 The Enola Earthquake Swarm began on January 12, 1982, and continued throughout the year with over 19,000 events recorded during this period by a temporary network of seismographs deployed in the area. The epicenters generally cluster in an area near the town of Enola, Arkansas. Ninety-three events were felt by local residents during 1982. The largest event of the swarm was a Magnitude 4.5 earthquake that occurred on January 20, 1982, with a maximum intensity of VI and felt over an area of approximately 75,000 km² in Arkansas, Missouri and Mississippi. Statements below list the reported intensities, locations and summarize the strongest effects of the Magnitude 4.5 earthquake: Intensity VI: Arkansas: Enola, Naylor. Report on State Highway 36 of hairline cracks in a concrete cellar, some tiles fell off a tile-lined well, a cracked fireplace, and minor cracks at the seams of sheetrock walls. Intensity V: Arkansas: Damascus, Drasco, Greenbrier, Guy, Holland (press report), Mount Vernon, Newport (press report), Pangburn, Rosebud, Ward. Reports of a few small objects were overturned and fell; windows, doors, or dishes were rattled and a few cracked windows. Intensity IV: Arkansas: Bauxite, Beebe, Bee Branch, Bigelow, Bradford, Cabot, Cave City, Choctaw, Clinton, Concord, Conway, Cotter, Cotton Plant, Des Arc, Dogpatch, Dyer, Edgemont, El Paso, Everton, Fox, Harriet, Harrison, Heber Springs, Hector, Hickory Ridge, Higden, Huntsville (press report), Kensett, Kingston, Lepanto, Leslie, Litona, Marshall, McRea, Morrilton, Mountain View, Naylor (press report), Newark, Pindall, Quitman, Reyno, Rosie, Searcy, Smithville, Vilonia, Walnut Ridge, Wilburn, Yellville. Missouri: Alton. Intensity III: Arkansas: Almyra, Austin, Batesville, Brandy, Brickeys, Caldwell, Calico Rock, College Station, Conway, (Hendrix College), Desha, Donaldson, Guion, Imboden, Keo, Little Rock, Madison, Malvern, Mammoth Spring, Mayflower (press report), Maynard, Melbourne, Oil Trough, Palestine, Patterson, Pleasant Plains, Pocahontas, Prim, Pruitt, Ridgedale, Romance, Sheridan, Shirley, Sulphur Rock, Sweet Home, Tumbling Shoals, Swifton, Viola, Wolf Bayou. Mississippi: Robinsonville. Missouri: Bakersfield, Caufield. Intensity II: Arkansas: Glenwood, Mount Pleasant. Missouri: Koshkonong, Myrtle. Felt: (indicates that the available data is not sufficient for assigning an intensity value) Arkansas: Black Rock, Durham. Adapted from Stover, C. W., 1985, United States Earthquakes, 1982, United States Geological Survey: United States Geological Survey Bulletin 1655, 141 p. Earthquake Description I II III IV V VI IX VIII VII X+ Modified Mercalli Intensity Scale Not felt. Felt by persons at rest, on upper floors, or favorably placed. Felt indoors. Hanging objects swing. Vibration like passing of light trucks. Duration estimated. May not be recognized as an earthquake. Hanging objects swing. Vibration like passing of heavy trucks; or sensation of a jolt like a heavy ball striking the walls. Standing automobiles rock. Windows, dishes, doors rattle. Glasses clink. Crockery clashes. In the upper range of IV, wooden walls and frame creak. Felt outdoors; direction estimated. Sleepers awakened. Liquids disturbed, some spilled. Small unstable objects displaced or upset. Doors swing, close, open. Shutters, pictures move. Pendulum clocks stop, start, change rate. Felt by all. Many frightened and run outdoors. Persons walk unsteadily. Windows, dishes, glassware broken. Knickknacks, books and other items fall off shelves. Pictures fall off walls. Furniture moved or overturned. Weak plaster and Masonry D cracked. Small bells ring (church, school). Trees, bushes shaken (visibly, or heard to rustle). Difficult to stand. Noticed by drivers of automobiles. Hanging objects quiver. Furniture broken. Damage to Masonry D, including cracks. Weak chimneys broken at roof line. Fall of plaster, loose bricks, stones, tiles, cornices (also unbraced parapets and architectural ornaments). Some cracks in Masonry C. Waves on ponds; water turbid with mud. Small slides and caving in along sand or gravel banks. Large bells ring. Concrete irrigation ditches damaged. Steering of automobiles affected. Damage to Masonry C; partial collapse. Some damage to Masonry B; none to Masonry A. Fall of stucco and some masonry walls. Twisting, fall of chimneys, factory stacks, monuments, towers, elevated tanks. Frame houses moved on foundations if not bolted down; loose panel walls thrown out. Decayed piling broken off. Branches broken from trees. Changes in flow or temperature of springs and wells. Cracks in wet ground and on steep slopes. General panic. Masonry D destroyed; Masonry C heavily damaged, sometimes with complete collapse; Masonry B seriously damaged, and damage to Masonry A. (General damage to foundations.) Frame structures, if not bolted, shifted off foundations. Frames racked. Serious damage to reservoirs and underground pipes broken. Conspicuous cracks in ground. In alluvial areas sand and mud ejected, earthquake fountains, sand craters. Most masonry and frame structures destroyed with their foundations. Some well-built wooden structures and bridges destroyed. Serious damage to dams, dikes, embankments. Large landslides. Water thrown on banks of canals, rivers, lakes, etc. Sand and mud shifted horizontally on beaches and flat land. Rails bent slightly. XI. Rails bent greatly. Underground pipelines completely out of service. XII. Damage nearly total. Large rock masses displaced. Lines of sight and level distorted. Objects thrown into the air. Masonry A: Good workmanship, mortar, and design; reinforced, especially laterally, and bound together by using steel, concrete, etc.; designed to resist lateral forces. Masonry B: Good workmanship and mortar; reinforced, but not designed in detail to resist lateral forces. Masonry C: Ordinary workmanship and mortar; no extreme weaknesses like failing to tie in at corners, but neither reinforced nor designed against horizontal forces. Masonry D: Weak materials, such as adobe; poor mortar; low standards of workmanship; weak horizontally. Adapted from Association of Bay Area Governments (ABAG), On Shaky Ground, 2003, Retrieved January 28, 2008 from http://www.abag.ca.gov/bayarea/eqmaps/doc/mmi.html. Association of Bay Area Governments (ABAG), On Shaky Ground, 2003, Retrieved January 28, 2008 from http://www.abag.ca.gov/bayarea/eqmaps/doc/mmi.html. Johnson, A., and Metzger, A., 1982, The Central Arkansas earthquake swarm—Part 1, 12 th January to 12 th July 1982: Tennessee Earthquake Information Center (TEIC), Special Report, no. 8, 84 p. Stover, C. W., 1985, United States Earthquakes, 1982, United States Geological Survey: United States Geological Survey Bulletin 1655, 141 p. Wood, H. O., and Neumann, Frank, 1931, Modified Mercalli Intensity Scale of 1931: Seismological Society of America Bulletin, v. 21, no.4, p. 277–283. References Intensity, as applied to earthquakes, represents a quantity determined from the effects on people, man-made objects, and the earth’s surface. Intensities are assigned according to descriptions listed in the Modified Mercalli Intensity (MMI) Scale of 1931 (Wood and Newman, 1931). There were originally twelve discreet steps, but only ten are recognized by the United States Geological Survey (USGS) in the modern MMI scale. Intensity ratings are expressed as Roman numerals between I at the low end and X+ at the high end of the scale. An earthquake in a populated area will have different intensities at different localities, owing to the distance from the focus of the earthquake, type of focal mechanism, local geological conditions, structural design of buildings, and the earthquake magnitude and duration (Stover, 1985). MMI maps illustrate the areal pattern of intensity associated with individual earthquakes. This map was adapted from the Modified Mercalli Intensities map by Arch Johnson and Ann Metzger, in the Tennessee Earthquake Information Center (TEIC) Special Report #8. About the Map