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APPROXIMATELIMIT OF

FELT AREA

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§̈¦540§̈¦55

§̈¦430 §̈¦540§̈¦630

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Little Rock

Jonesboro

Fort Smith

Rogers

Conway

Fayetteville

Pine Bluff

Bella Vista

Texarkana

Springdale

Paragould

SearcyRussellville

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

EtowahBay

Ashdown

Kibler

Stuttgart

PiggottPea 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 BudEarle

Prairie Grove

Haskell

Arkadelphia

De Queen

Elkins

Greers Ferry

Heber Springs

Rosston

Amity

Chidester

Dyer

Hazen

OlaDanville

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 KnobLondon

Bull Shoals

Dumas

Sheridan

Dermott

Stamps

Cushman

Eudora

Corinth

Decatur

Cave Springs

Rockport

Branch

Salem

Smackover

Parkin

Cotter

Bodcaw

Lost BridgeVillage

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

CoalHill

Sidney

Viola

Grady

Lockesburg

Reader

Elm Springs

Hughes

Stephens

DesArc

Black Rock

Madison

Calico Rock

Greenland

Prairie Creek

Menifee

Little Rock Air Force Base

BonoMarshall

Cave CityLincoln

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

RavendenBriarcliff

Wiederkehr Village

Mount Pleasant

Casa

Portia

Fouke

England

Austin

Newark

Winslow

McCrory

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

DyessWilson

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

WinthropKingsland

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

CaveSprings

Jasper

Western Grove

Blue Mountain

Mammoth Springs

MountVernon

Peach Orchard

Bellefonte

Minturn

Antoine

Swifton

Widener

Smithville

Friendship

Magness

Ozan

KnobelRavenden Springs

Havana

Everton

Lead Hill

Ulm

Tinsman

Sulphur Springs

KeiserChester

OgdenBanks

Egypt

Letona

St. Paul

Cherry ValleyPangburn

Donaldson

Scranton

Gilbert

Omaha

Cash

Almyra

Pleasant Plains

Lonsdale

Griffithville

Roe

Aubrey

Springtown

Hickory Ridge

McNab

Sedgwick

Joiner

Winchester

Midland

Jericho

FountainHill

Pollard

Victoria

Tupelo

West Point

Black Oak

EastCamden

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

CammackVillage

Powhatan

Patmos

La Grange

Whelen Springs

Jerome

Rudy

Summers

WaldenburgAmagon

South Lead Hill

Horseshoe Lake

Mitchellville

Cane Hill

Anthonyville

Evansville

Salem Springs

Oakhaven

Cincinnatti

MorrowDutch Mills

Litteral

DurhamSulphur City

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Modified Mercalli IntensitiesEnola Earthquake Swarm

Seismic Event: Magnitude 4.520 January 1982 @ 6:33 PM CST

(N

GH-EQ-MMI-AR-0001

10 0 10 20 30 40 50 605Miles

10 0 10 20 30 40 50 605Kilometers

Arkansas Geological SurveyBekki White, Director and State Geologist

Symbols

_̂ Earthquake Epicenter

Interstates

US Highways

State Highways

Incorporated Areas

¡¢62

§̈¦4 0

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 IVModerate

VStrong

Light

VIVery

StrongModerate

VII

ModerateHeavy

SevereVIII

ExtremeX+

Violent

Heavy

IXWeak

None

III

VeryLight

VeryHeavy

1.5 2 2.5 3 3.5 4 4.5 5 5.5 6 6.5 7+

INTENSITYSHAKINGDAMAGE

MAGNITUDEBy

Scott M. Ausbrooks and Erica Doerr2009

1 : 850,000 Jerry W. ClarkDate: 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

IIIIII

IV

V

VI

IX

VIII

VII

X+

Modified Mercalli Intensity ScaleNot 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, 12th January to 12th 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.

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