Liquefaction Evidence for One or 

More Strong Holocetie Earthquakes 

in the Wabash Valley of Southern 

Indiana incj Illinois, with a

T"1^ II * "*' 1*'* * if* l-^v*^^lITYIi Y\ o t^\f «''-d-'f"it'TY^O'^iE^ ^\T JTrcilllllllidl y ILmMIld:lv> OI
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STENNIS SPACE CENTER, Mississippi-Bldg. 3101
Liquefaction Evidence for One or 

More Strong Holocene Earthquakes 

in the Wabash Valley of Southern 

Indiana and Illinois, with a 

Preliminary Estimate of Magnitude

By S.F. OBERMEIER, J.R. MARTIN, A.D. FRANKEL, T.L. YOUD, PJ. MUNSON, 

C.A. MUNSON, and E.G. POND

U.S. GEOLOGICAL SURVEY PROFESSIONAL PAPER 1536

A 175-km span of liquefaction features centered 

near Vincennes, Ind,, is interpreted to have been 

caused by one or more large earthquakes that 

occurred between 1,500 and 7,500 years ago

UNITED STATES GOVERNMENT PRINTING OFFICE, WASHINGTON: 1993
U.S. DEPARTMENT OF THE INTERIOR 

BRUCE BABBITT, Secretary

U.S. GEOLOGICAL SURVEY 

Dallas L. Peck, Director

Any use of trade, product, or firm names in this publication is for

descriptive purposes only and does not imply endorsement by the

U.S. Government

Library of Congress Cataloging in Publication Data

Liquefaction evidence for one or more strong Holocene earthquakes in the Wabash Valley of southern Indiana and Illinois, with

a preliminary estimate of magnitude / by S.F. Obermeier ... [et al.].

p. cm.—(U.S. Geological Survey professional paper ; 1536) 

Includes bibliographical references. 

Supt. of Docs. no. : I 19.16: 1536

1. Dikes (Geology)—Indiana—Vincennes region. 2. Soil liquefaction—Indiana—Vincennes region. 3. EarthquakesIndiana—Vincennes region. 4. Geology, Stratigraphic—Holocene. I. Obermeier, Stephen F. II. Series. 

QE611.5.U6L57 1993 92-40578 

551.2'2'0977239-dc20 CIP

For sale by Book and Open-File Report Sales, U.S. Geological Survey, 

Federal Center, Box 25286, Denver, CO 80225
CONTENTS

Page

Abstract..................................................................................................................... 1

Introduction................................................................................................................ 1

Results...................................................................................................................... 3

Description of Features .......................................................................................... 3

Ages of Features................................................................................................... 5

Origin of Features ....................................................................................................... 8

Evidence for Seismic Origin .................................................................................... 8

Seismic versus Alternative Origins........................................................................... 9

Artesian Conditions ......................................................................................... 9

Morphology of the Dikes and Sand Blows ...................................................... 9

Role of Topography and Geology on Ground-Water Conditions.......................... 10

Nonseismic Landsliding.................................................................................... 15

Sudden Lowering of River Level........................................................................ 17

Syndepositional Processes, Weathering, and Frost................................................ 17

Paleoseismic Implications.............................................................................................. 18

Source Region....................................................................................................... 18

Strength of Earthquake(s)....................................................................................... 18

Conclusions................................................................................................................. 25

Acknowledgments........................................................................................................ 25

References Cited......................................................................................................... 26

ILLUSTRATIONS

FIGURES 1, 2. Maps showing:

1. Areas that were searched for liquefaction features, sites where liquefaction features were discovered, and

maximum dike widths........................................................................................................................... 2

2. Generalized locations, within the study area, of major fluvial and slack-water deposits near the Wabash and

Ohio Rivers........................................................................................................................................ 4

3. Vertical section showing general characteristics of buried dikes with their vented sediments along the Wabash River .... 5

4. Grain-size curves for samples collected in the suspected coarsest source stratum in the Wabash Valley (at Site RF)

and for samples collected from the coarsest stratum at a site at Whiskey Springs, Idaho...................................... 6

5, 6. Vertical sections showing:

5. Schematic relations for largest dikes and associated vented sandy materials at sites ranging from frequently

flooded to rarely flooded ....................................................................................................................... 7

6. Anticipated relation of dikes and vented sediments from recurrent earthquake-induced liquefaction at an

alluviating site .................................................................................................................................... 8

7. Aerial photograph of a portion of the Manila, Ark., 7.5-minute orthophotographic quadrangle showing fissures and

sand blows that formed in response to liquefaction during the 1811-12 New Madrid earthquakes.......................... 11

8. Aerial photograph and topographic map of Site VW (southwest of Vincennes, Ind.) showing relation of strike of dikes

to meander scrolls of point-bar deposits, and photographs of the widest dike at the site...................................... 12

9. Aerial photograph, topographic map, and vertical section showing location and geologic setting of dikes at Site PB,

Wabash County, 111.................................................................................................................................. 14

10. Aerial photograph, topographic map, and plan view of pit showing physical setting and location of dikes at Site GR,

Posey County, Ind................................................................................................................................... 16

11. Graph showing earthquake moment magnitude versus epicentral distance to farthest liquefaction feature.................... 24

ill
IV CONTENTS

TABLES

TABLES 1. RATTLE results for amplification of horizontal acceleration in soil with respect to bedrock in the Wabash Valley—————— 20

2. RATTLE results for amplification of horizontal acceleration in soil with respect to bedrock near Charleston, Mo. —————— 20

3. SHAKE results for amplification of horizontal acceleration in soil with respect to bedrock in the Wabash Valley——————— 21

4. SHAKE results for amplification of horizontal acceleration in soil with respect to bedrock near Charleston, Mo. ——————— 21

5. Comparison of liquefaction effects with factors controlling liquefaction for earthquakes in the Central and Eastern

United States _____________________________________________________________ 22

ABBREVIATIONS USED IN THIS REPORT

Abbreviation Meaning

cm centimeter

ft feet

g gram

g gravitational acceleration

Hz hertz

in inch

ka thousand years

kg kilogram

m meter

m^ body-wave magnitude

Mw moment magnitude

Q quality factor

s second

t* traveltime

ACT difference in stress
LIQUEFACTION EVIDENCE FOR ONE OR MORE STRONG HOLOCENE 

EARTHQUAKES IN THE WABASH VALLEY OF SOUTHERN INDIANA 

AND ILLINOIS, WITH A PRELIMINARY ESTIMATE OF MAGNITUDE

By S.F. OBERMEiER, 1 J.R. MARTIN, 2 A.D. FRANKEL, 1 T.L. YouD,3 PJ. MuNSON,4 C.A. MuNSON,4 and

E.G. POND2

ABSTRACT

We have discovered hundreds of planar, nearly vertical sand- and 

gravel-filled dikes that we interpret to have been caused by 

earthquake-induced liquefaction in the Wabash Valley of southern 

Indiana and Illinois. These dikes range in width from a few centimeters 

to as much as 2.5 meters. The largest dikes are centered about the 

general area of Vincennes, Ind.; they decrease in size and abundance to 

the north and south of this area. Preliminary studies indicate that it is 

highly possible that many, if not all, of the dikes were formed by a 

single large earthquake that took place in the Vincennes area sometime 

between 1,500 and 7,500 years ago. The severity of ground shaking 

required to have formed the observed dikes far exceeds the strongest 

level of shaking of any earthquake in the Central United States since 

the 1811-12 New Madrid earthquakes. Our engineering-seismologic 

analysis, based on comparison of liquefaction effects with those of 

historic earthquakes in the Central and Eastern United States, indicates that the moment magnitude of the prehistoric earthquake was on 

the order of 7.5.

INTRODUCTION

Many small and slightly damaging earthquakes have 

occurred throughout the region of the lower Wabash 

River valley of Indiana and Illinois during the 200 years 

of historic record. Seismologists have long suspected that 

the Wabash Valley seismic zone (a weakly defined area 

of seismicity delineated by Nuttli (1979), inset in fig. 1) 

could be capable of producing earthquakes much 

stronger than the largest of record (mb 5.8, Mw 5.5; 

Hamilton and Johnston, 1990). No Pleistocene faults 

have been discovered in the region. However, because 

strong earthquakes in the central and eastern parts of 

the United States usually do not produce surface faulting, other paleoseismic effects must be used to detect 

prehistoric earthquakes. For this purpose, a search for

Manuscript approved for publication, October 5, 1992.

1U.S. Geological Survey.

2Virginia Polytechnic Institute and State University.

3Brigham Young University.

4Indiana University.

earthquake-induced paleoliquefaction features was initiated in 1990 and continued in 1991 (Obermeier and 

others, 1991; Munson and others, 1992). The search has 

been mainly in the lower Wabash River valley and its 

tributaries and, to a lesser extent, in the lower Ohio 

River valley.

The Wabash Valley seismic zone contains the Wabash 

Valley fault zone, which is made up of numerous northeasterly trending normal faults. Many studies have 

shown the age of these Wabash Valley faults to be 

post-Pennsylvanian and pre-Pleistocene (Bristol and 

Treworgy, 1979). A much older generation of normal 

faulting, which possibly is related to the initial opening of 

the New Madrid rift complex, may extend into basement 

rocks beneath the Wabash Valley fault zone and beyond 

the fault zone throughout much of southwestern Indiana 

(Sexton, 1988). Some researchers suggest that the deepest earthquakes are related to the reactivation of the rift 

complex (Taylor, 1991). Historical earthquake epicenters 

are rather scattered and do not show good correspondence with known geologic structures. Overall, the seismotectonic setting is poorly known.

The Wabash River valley (fig. 2), which lies along the 

central axis of the Wabash Valley seismic zone, provides 

a very good environment for formation and preservation 

of liquefaction features. Alluvium in the valley as thick as 

10 to 30 m lies on bedrock at many places. The valley 

contains extensive expanses of low, late Pleistocene 

terraces (glaciofluvial braid-bar deposits, mainly gravel 

and gravelly sand) into which are inset slightly lower 

Holocene flood plains (point-bar sediments, mainly sandy 

gravel, gravelly sand, and sand). The larger rivers have 

meandered back and forth over a relatively wide belt 

throughout the Holocene and have left behind deposits of 

various ages. The sand and gravel deposits of both braid 

bars and point bars are normally overlain abruptly by 2 

to 5 m of fine-grained (sandy silt to clayey silt) alluvium, 

which is made up mainly of overbank deposits. Bordering
HOLOCENE EARTHQUAKES IN THE WABASH VALLEY OF SOUTHERN INDIANA AND ILLINOIS

northern limit of study 

along Wabash River

Searched sand pit 

Searched sand pit containing dikes 

Region of localized search of stream bank 

Maximum dike width at site containing 

1 to 29 dikes: >60 cm (•); 30-59 cm (•) 

15-29 cm {•); 5-14 cm (•); <5 cm (•)

eastern limit of study 

along White River

KENTUCKY,

Indianapolis

O 

Terre Haute Wabash Valley

seismic

zone

0 10 20 30 40 50 MILES

T I \ I I 

0 10 20 30 40 50 60 70 KILOMETERS
RESULTS

the valley at the level of glaciofluvial deposits and 

slightly higher are extensive plains of fine-grained deposits (mainly silt and clay, but sand locally) that were laid 

down in slack-water areas during glaciofluvial alluviation. The water table appears to have been relatively 

shallow (<3 m deep) over large parts of the valley during 

much of the time following glaciofluvial alluviation, on 

the basis of the depth of weathering profiles (leaching of 

carbonates and B-horizon development) in the sandy and 

silty alluvium. This combination of meandering rivers, a 

relatively shallow water table, and the presence of 

widespread, thick, clean (no clay) sand deposits at shallow depths with an overlying fine-grained cap has provided an excellent opportunity for liquefaction features 

to form in response to strong earthquake shaking 

throughout much of the Holocene.

Discussed below are results of our search for liquefaction features, our reasons for interpreting these features 

as earthquake induced, and our interpretations of the 

epicentral region and strength of the earthquakes that 

produced the features. Information in this report is 

based on data available in February 1992.

RESULTS

More than 200 dikes formed by liquefaction and several 

sills have been found in Holocene point-bar, late Pleistocene glacial outwash, and late Pleistocene slack-water 

deposits. Figure 1 shows the locations we searched, sites 

where dikes were discovered, and the size of the largest 

dike observed at each of the sites. Nearly all sites shown 

on figure 1 have more than 1 dike, and many sites have 

more than 10. Almost all the outcrops searched were in 

actively eroding banks of rivers, but a few sand and

FIGURE 1.—Areas that were searched for liquefaction features, 

sites where liquefaction features (dikes and sills) were discovered, 

and maximum dike widths. Sites having dikes are labeled with 

capital letters; size of bullet indicates largest dike width. A 

continuous search of Wabash River banks was made from the 

confluence with the Ohio River northward to the limit shown on 

the map; a continuous search of White River banks was made from 

the confluence with the Wabash River eastward to the limit shown 

on the map. The banks along the Wabash and White Rivers in most 

places overlie moderately liquefiable sediments. Outcrop quality 

was highly variable but was generally good along the Wabash 

River, except for the 25-km-long portion noted on the map. 

Outcrop quality was generally very poor along the White River 

because of extensive bank slumping. Sites of localized searching 

are denoted by symbols in the explanation. Outcrop quality at sites 

of localized searching along the Ohio River was excellent, and even 

small dikes would have been detected. Sites in the southern part of 

the study areas, where dikes might have been induced by the 

1811-12 New Madrid earthquakes, are designated with question 

marks. Dike width shown on the figure is the width measured at 

least 1 m above the base of the dike; where the base of the dike was 

not exposed, the listed width was the maximum observed.

gravel pits and banks of recently excavated ditches were 

searched also.

DESCRIPTION OF FEATURES

Virtually all features that we interpret as having a 

seismically induced liquefaction origin are planar sand- or 

sand-and-gravel-filled dikes that are vertical to steeply 

dipping and connect to a sediment source at depth (fig. 

3). The dikes cut through the low-permeability cap that 

overlies thick source strata of silty to gravelly sand (and 

possibly sandy gravel). Many dikes extend upward as 

much as 4 m above the source zone. Sediment has vented 

from the dikes at many places to form "sand blows," but 

many smaller dikes pinch out before reaching the surface, and erosionally truncated dikes are also fairly 

common. Large quantities of gravel (maximum diameters as great as 4 cm) were vented from many dikes. Dike 

widths (measured at least 1 m above the source bed) 

exceed 30 cm at 11 sites and exceed 60 cm at 4 sites. The 

maximum observed width was 2.5 m. Sidewalls of many 

dikes are parallel, especially at larger dikes. The grain 

size of an individual dike filling can be any one of the 

following: silty fine sand, sand, sand with a small amount 

of gravel, gravel with a trace of sand, or gravelly sand 

containing as much as 10 percent silt and clay. Many 

dikes contain clasts of sidewall material that were transported upward. The sediment within the dikes is almost 

everywhere structureless, except that some of the elongate gravels and clasts derived from sidewall material 

tend to be oriented vertically. Where gravel or coarse 

sand is present, there is generally a fining upward 

sequence of coarsest material. Within many dikes there 

are sharply defined, vertically intertwined and intersecting zones containing distinctly different grain sizes. 

Sometimes the zones can be traced to different source 

strata at depth.

Sediment vented from the dikes produced sand blows 

that are as much as 40 m wide. Thicknesses of 0.15 to 0.2 

m are not unusual near the vent. Most sand blows fine 

upward significantly in the vicinity of the dike and 

become finer laterally, especially if gravel was vented. 

Still, gravels as large as 2 cm in diameter can be traced 

as far as 5 m from a vent. At sites where many sand 

blows are present, the sand-rich blows are generally 

much larger than those more gravel rich, in terms of 

volume of sediment vented onto the ground surface.

Only eight sites having sills were observed in our 

study. Sills generally branch steeply upward and irregularly from the main dike and crosscut stratigraphic 

horizons. At a few sites though, the sills are subhorizontally extensive. Boundaries of the sills are sharply 

defined and usually show little or no evidence of weathering after their formation. Sand blows, in contrast, are
HOLOCENE EARTHQUAKES IN THE WABASH VALLEY OF SOUTHERN INDIANA AND ILLINOIS

o 10 20 30 40 50 MILES

I

I I I I I I I 

0 10 20 30 40 50 60 70 KILOMETERS
RESULTS

underlain at the base by a paleosol, and the vented 

sediments have at least some evidence of pedogenic 

alteration (see fig. 5).

At widely scattered sites we have observed the source 

strata that provided sediment that flowed into the dikes. 

(A prolonged drought caused the water table to be 

extremely low during our period of fieldwork, so we were 

able to view these strata, which would otherwise have 

been submerged.) The most finely grained source stratum is a silty fine- to medium-grained sand that has a 

trace of clay. Most source strata are much coarser and 

contain at least some pebbles. Gravel is a common 

constituent. Site RF has exceptionally coarse source 

deposits that contain as much as 60 percent gravel (fig. 

4).

The vented sediments at sites bordering the Wabash 

River generally are buried beneath a 1- to 3-m thickness 

of overbank deposits. On slightly elevated terraces, 

where flooding is rare, the vented sediments have been 

incorporated into the surface soil. Figure 5 shows soil 

relations for sand blows vented onto ground surfaces at 

sites ranging from frequently to rarely flooded. Also 

shown are our tentative interpretations of stratigraphic 

and age relations. The principal basis for determination 

of the age of the surface onto which sand blows vented is 

discussed in the following section.

AGES OF FEATURES

Munson and others (1992) examined 24 liquefaction 

sites along the lower and central Wabash River and the 

White River and concluded, on the basis of the stratigraphic and pedological characteristics of the sites and 

archaeological and radiometric dating, that most, if not 

all, of the liquefaction features in those areas resulted 

from a strong earthquake that occurred sometime 

between 1.5 and 7.5 ka. An additional 11 sites, discovered along Skillet Fork and lower Embarras River in 

southeastern Illinois (fig. 1), are similar in characteristics; their locations and maximum dike sizes suggest that 

they resulted from the same event. Additionally, at one 

of the Illinois sites (WC) the dikes were erosionally 

truncated by a later stream channel, and a small log in 

the fill of this channel and directly above the dikes has 

been radiocarbon dated as 2.25±0.07 ka (ISG-2191).

FIGURE 2.—Generalized locations, within the study area, of major 

fluvial and slack-water deposits near the Wabash and Ohio Rivers. 

Dotted areas show locations of late Wisconsinan outwash sand and 

gravel and Holocene alluvial silt, sand, and gravel, with subordinate amounts of clay. Shaded areas show locations of late Wisconsinan slack-water deposits, which are mainly clay and silt, and, 

locally, sand. Map units taken from Gray and others (1991).

0 ___ ___ Pedo-mix zone ___ ___

• - ! .' .0 „' . • ' ••'••'.'.«.'.

--- ' - 0 . • • °' •• ••• • ••

. * ' Q' . "/ Blocky soil structure

JO' . '

W '4'" -^ Broken pieces of 

'"• ' '° P- X sidewall material '•o'o • ' 'o

. ' . . '. 0. .'• 

Yellowish-brown silty loam /f- o,. • • Q . •' • /) ^?- • _

FIGURE 3.—Diagrammatic vertical section showing the general characteristics of buried sand- and gravel-filled dikes with their vented 

sediments along the Wabash River. Source beds are Holocene 

point-bar deposits or late Wisconsinan braid-bar deposits overlain by 

much finer overbank sediment. The sediments in source beds 

beneath dikes show evidence of flowage into dikes. At many places, 

the gravel content and size decrease upward in dikes. The extreme 

upper portion of a dike often is widened and shows evidence of 

ground shattering. The column on the right side of the figure 

contains pedological descriptions.

Pedological data argue for some antiquity for the 

liquefaction features throughout the area, for there is 

typically a moderately to strongly developed B horizon 

either in sediments in the dikes, in sand-blow deposits, 

or in sediments overlying sand blows (figs. 3 and 5). By 

comparison, there is no discernible B-horizon development in sediments vented during the earthquakes of 

1811-12, in the New Madrid area. Only three sites in the
HOLOCENE EARTHQUAKES IN THE WABASH VALLEY OF SOUTHERN INDIANA AND ILLINOIS

GQ 

CC

O

CC

EXPLANATION

Curves for test pit samples 1 and 2 from 

Site RF in the Wabash Valley

Curves for test pit samples 3 and 4 from 

the Whiskey Springs liquefaction site

100 10

GRAIN SIZE (IN MILLIMETERS)

FIGURE 4.—Grain-size curves for samples collected in the suspected 

coarsest source stratum in the Wabash Valley (at Site RF) and for 

samples from the coarsest source stratum (at Whiskey Springs) that 

liquefied and formed sand blows in response to the 1983 surface wave

Wabash Valley seismic area (SR I, SR II, SH), all with 

dikes that pinch out beneath the zone of weathering, and 

all located southwest of the confluence of the Wabash 

with the Ohio River and nearest the 1811-12 New 

Madrid earthquakes' epicentral region, are possibly of 

1811-12 origin.

The strongest argument that favors all of the Wabash 

Valley features having been generated by a single earthquake is the stratigraphic positions of the sand blows at 

the sites. At none of the sites have we observed venting 

upon more than a single paleosurface. Many of the sites 

are in Holocene flood-plain settings where multiple episodes of sedimentation and soil development have produced one to three discernible paleosurfaces (as well as 

the modern surface). Engineering and geologic studies 

have shown that liquefaction often recurs at or near the 

same places for earthquakes that are both closely and 

widely separated in time (Kuribayashi and Tatsuoka, 

1975; Youd and Hoose, 1978; Youd, 1984; Saucier, 1989; 

Obermeier and others, 1990; Tuttle and others, in press). 

If earthquakes separated in time caused the Wabash 

Valley dikes, it would be anticipated that dikes would 

have vented at various stratigraphic levels at the sites, in 

a manner similar to that illustrated in figure 6. Although 

we have observed at several sites ambiguous indications 

that liquefaction possibly occurred multiple times (such

magnitude 7.3 Borah Peak, Idaho, earthquake (Andrus and others, 

1991). The stratum at Whiskey Springs appears to have the coarsest 

deposits, worldwide, that are documented to have liquefied, flowed, 

and formed sand blows.

as dikes containing sharply defined zones having different grain sizes), such occurrences might be explained by 

strong aftershocks.

A single large earthquake is also suggested by the 

concentration of exceptionally large liquefaction dikes 

(>60 cm wide) along the Wabash River from Site RF 

southward as far as Site CF, a distance of about 35 km. 

The span of exceptionally large dikes may well extend 

farther southward, but there is an absence of outcrops 

from Site CF almost to Site PB, a distance of more than 

25 km. If the single large earthquake hypothesis is 

correct, very large features also should have formed in 

the lowermost portion of the White River valley. Large 

features have been found in this lowermost portion at 

only one site. However, outcrops are so limited in both 

number and length along this river that a statistically 

meaningful characterization of sizes and abundance of 

liquefaction features is not yet possible.

An alternative mechanism that might explain the 

apparent synchronism and the distribution of the liquefaction features in the Wabash Valley would be that 

scattered strong earthquakes occurred throughout the 

region at approximately the same time, comparable to 

the situation in which four exceptionally (Mw> about 8) 

strong earthquakes occurred over a 3-month period in 

the New Madrid area in 1811-12. That mechanism is
RESULTS

SITE VW SITE PB SITE GR

Last Glacial Flood Surface

•?!,.,, • • brown A

//' disturbed • . A

/i zone . . sandy silt with pebbles t *

Secondary \

soil lamellae N

'with brown iron N

and humic stains \

•'•..* .light gray sand & gravel strata '".' /•'?? "^>> 

(glaciofluvial outwash, _ _ _ _ 7

• • • light gray sand & gravel strata . 

(Wabash River point-bar deposits

FIGURE 5.—Vertical section showing schematic relations for largest 

(widest) dikes and associated vented sandy materials at three sites, 

ranging from frequently flooded (Site VW) to infrequently flooded 

(Site PB) to rarely flooded (Site GR). Also shown are locations and 

tentatively estimated ages of paleosurfaces and soil descriptions. 

Width of vented sediments is as much as 40 m and is much larger 

than depicted. (Sketch and soil interpretations provided by Leon R. 

Follmer and Wen-June Su, Illinois State Geological Survey.) Pedomix zones have sand-rich cores of vented sediments containing minor 

silt and clay; this zone is surrounded by a zone of increasingly lower

sand content. The highest concentration of sand and pebbles is on the 

paleosol surface. Presence of the pedo-mix zone represents passage of 

time before burial by overbank deposits. The paleosol surface onto 

which sediments vented has an estimated age of 4 to 7 ka that is based 

primarily on radiometric and archaeological data. At Site VW, the 

contact having the age of 1 to 3 ka is estimated on the basis of 

archeological and pedological data. At Site PB, the inceptisol below the 

sand blow is estimated to be 7.5 ka on the basis of radiometric data. At 

Site GR, the age of the present surface is estimated to be 10.5 to 12 ka 

on the basis of geological and archaeological data.

Designations for the B horizon are described below:

B B horizon, the zone of alteration below topsoil or main root zone in soil profiles that shows color and 

morphological changes in comparison to original material (parent material). B-horizon soil normally 

appears as a relatively uniform zone of blocky aggregates in loose or compact form.

Bg The gleyed variation of B horizon that is dominated by gray colors and indicates seasonal or 

permanent wetness.

Bt B horizon variation that has evidence of clay accumulation (clay skins).

Bx B horizon variation that is brittle and very hard when dry and softens upon wetting.

B(ox) B horizon variation that shows evidence of oxidation; other features such as Bt or Bx are usually 

weak or absent or are not designated.
HOLOCENE EARTHQUAKES IN THE WABASH VALLEY OF SOUTHERN INDIANA AND ILLINOIS

V/ U/, ill III // Aft

Overbank or channel deposits, 

silt or clay

Source sand .

FIGURE 6. —Vertical section showing anticipated relation of dikes and vented sediments from recurrent earthquake-induced liquefaction at an

alluviating site. (No comparable relations were observed in the Wabash Valley.)

being considered as our research continues, but it is to be 

noted that the 1811-12 earthquake pattern is very 

unusual among historically known earthquakes.

ORIGIN OF FEATURES

Criteria that we use to interpret an earthquake origin 

to the dikes and sand blows in the Wabash Valley are 

discussed in Obermeier and others (1990) and must satisfy the following points.

1. The features should have sedimentary characteristics that are consistent with earthquake-induced 

liquefaction origin; that is, there must be evidence of 

an upward-directed, strong hydraulic force that was 

suddenly applied and was of short duration.

2. The features should have sedimentary characteristics that are consistent with historically documented 

observations of the earthquake-induced liquefaction 

processes.

3. The features should occur in ground-water settings 

where suddenly applied, strong hydraulic forces of 

short duration could not be reasonably expected 

except from earthquake-induced liquefaction. In particular, such settings should be extremely unlikely 

sites for artesian springs.

4. Similar features should occur at multiple locations 

that preferably are at least within a few kilometers 

of one another and have similar geologic and groundwater settings. Where evidence of age of the event is 

present, it should support the interpretation that the 

features formed in one or more discrete, short episodes that individually affected a large area and that

the episodes were separated by long time periods 

during which no such features formed.

On the basis of these four criteria, the physical characteristics of the dikes in the Wabash Valley are consistent with what would be expected from a seismically 

induced liquefaction origin. These characteristics and the 

physical setting in which the dikes developed are 

described in the following section. Because mechanisms 

other than earthquakes can produce similar features, we 

also discuss alternative mechanisms in their formation 

and compare characteristics that would be expected from 

earthquake sources and alternative sources.

EVIDENCE FOR SEISMIC ORIGIN

Because a detectable vertical offset of sedimentary 

beds that make up the fine-grained caps cut by the dikes 

is rare, any ground movement associated with generation of the dikes must have been almost entirely horizontal. The presence of large dikes, many having parallel 

walls throughout the height of the dike, further indicates 

that the fine-grained caps moved laterally. On the basis 

of our many widespread field observations of flowage 

features in the source zones, we conclude that the lateral 

movement normally took place on thick strata of clean to 

slightly silty sand, gravelly sand, or sandy gravel. All 

these relations are typical of the mode of ground failure 

(lateral spreading) caused by earthquake-induced liquefaction. These features in the Wabash Valley are strikingly similar to dikes and lateral spreads generated by 

liquefaction during the 1811-12 New Madrid earthquakes (Obermeier and others, 1990; Leffler, 1991). The
ORIGIN OF FEATURES

only notable difference between dikes and sills in the 

Wabash Valley and liquefaction effects of the 1811-12 

earthquakes is that sills are commonplace in the epicentral region of the 1811-12 earthquakes but are exceptional in the Wabash Valley.

An earthquake-induced liquefaction origin for the 

dikes of the Wabash Valley is interpreted because of the 

following aspects, when considered in combination.

1. The dikes widen downward or have walls that are 

parallel.

2. Dikes are linear in plan view and exhibit strong 

parallel alignment in local areas.

3. The dikes vented large quantities of sandy sediment 

to the surface as sand blows.

4. Material in the dikes fines upward and was transported upward.

5. Bedding in some source beds is homogenized, and 

contacts with overlying fine-grained sediment are 

highly convoluted in some places.

6. Flow structures that project upward from the source 

zones of sand or sand and gravel into the bottom of 

the dikes can be observed in some places.

7. Some dikes occur in flat and elevated landforms that 

are located many hundreds to thousands of meters 

from any steep slopes that might have existed at the 

time of formation of the dikes. These sites are 

unlikely to have experienced high artesian pressures 

or nonseismic landsliding.

8. Other nonseismic mechanisms that could have produced similar features are not plausible, as we 

discuss in the following sections.

9. The size and abundance of the dikes along the 

Wabash River, which is the area where data are 

most complete, generally decrease with increasing 

distance from a central region of large dikes (fig. 1).

All these aspects of the dikes, including a core area of 

exceptionally large dikes, can be observed in the 1811-12 

New Madrid earthquakes' epicentral region, which has a 

physical setting similar to that of the Wabash Valley.

SCEISMIC VERSUS ALTERNATIVE ORIGINS

The following sections discuss in detail some characteristics of liquefaction-induced features that would be 

expected from a seismic origin and why artesian conditions, nonseismic landsliding, sudden lowering of the 

river level, and other nonseismic mechanisms have been 

considered and eliminated as sources of the dikes.

ARTESIAN CONDITIONS

Because elimination of significant nonseismic artesian 

pressures as a cause of liquefaction is important to our

arguments, we have developed a simplistic soil mechanics analysis that constrains the artesian pressures 

required to cause nonseismic lateral spreading in the 

Wabash Valley. At many sites, dikes formed in areas 

where the vertical change in height of the ground surface 

was no more than 1 to 2 m over horizontal distances 

greatly exceeding 200 m (0.5 to 2 percent). For such 

gentle slopes to have failed by a nonseismic mechanism, 

artesian pressures are required to have been so high as 

to permit essentially no soil strength in the failure zone of 

granular material beneath the fine-grained cap; such a 

condition would reduce effective stress in the failure zone 

to zero. Zero effective stress requires that the artesian 

head must approach twice the thickness of the finegrained cap above the failure zone. (This statement is 

based on the assumption that the wet unit weight of 

capping sediment is nearly double the unit weight of 

water.) The cap thickness is normally in the range of 2 to 

4 m and varies from 1.5 m to probably more than 5 m. 

Therefore, the artesian head must necessarily have 

approached 1.5 to 5 m in height above the ground 

surface, depending on cap thickness at the site.

Two independent forms of evidence are presented to 

determine the possible role of nonseismic artesian conditions in formation of dikes and sand blows. Both morphology of the features and characteristics of the physical 

settings are discussed.

MORPHOLOGY OF THE DIKES AND SAND BLOWS

Locally, some of the dikes widen into a shattered zone 

in their upper 0.1 to 0.2 m, just beneath the point at 

which sediment vented to the surface. This shattered 

zone is in the A and B horizons of the weathered soil that 

was at the ground surface at the time of venting. The 

coarsest materials (gravels) that were vented onto the 

paleosurface are often concentrated into or very near the 

basal portion of the sand blows (fig. 3). Near-surface 

shattering and upward fining of vented sediments are 

consistent with observations related to venting of sediments to the surface throughout the epicentral region of 

the 1811-12 New Madrid earthquakes. These characteristics are also consistent with forceful ejection of water 

and vented sediments during the early stage of venting, 

whereas forceful ejection during the early phase of 

venting would not necessarily be expected from artesian 

springs. Numerous dikes at widespread locations are 

filled with gravel that is surrounded by little or no finer 

sized material throughout the height of the dike. The 

gravels commonly range from 1 to 2 cm in diameter. This 

coarseness also attests to very forceful flow through the 

dikes.

The observation that the dikes in the Wabash Valley 

are approximately linear and subparallel in plan view
10 HOLOCENE EARTHQUAKES IN THE WABASH VALLEY OF SOUTHERN INDIANA AND ILLINOIS

also corresponds with the form of earthquake-induced 

liquefaction features produced by large historic earthquakes elsewhere. Figure 7 is an aerial photograph 

showing long fissures and individual sand blows that 

formed as a result of liquefaction during the 1811-12 New 

Madrid earthquakes. The long fissures on the aerial 

photograph are underlain by vertical sand-filled dikes 

that are very similar to those in the Wabash Valley. 

Even the individual sand blows, where formed on a 

clay-rich cap, are generally underlain by vertical, planar, 

sand-filled dikes of small width and substantial length in 

the horizontal plane (Obermeier, 1989, p. B50-B51), just 

as those of the Wabash Valley.

Figure 7 also shows how the fissure patterns are 

controlled by the local geologic setting. Seismically 

induced fissures have a strong tendency to form along 

the tops of and to be parallel to the scrolls of point-bar 

deposits, even at large distances (>1 km) from the 

stream channel (Fuller, 1912; Obermeier, 1989). Also, 

liquefaction-induced fractures tend to parallel the stream 

channel on both sides of the stream. Figure 8 shows the 

close relationship between the dikes and the morphology 

of point-bar deposits along the Wabash River. We found 

at least 10 places along the Wabash River where the 

dikes are parallel to the scrolls of the point bars and at 

the time of their formation were far back (>200-300 m) 

from banks of the river channel. Both strike and location 

of the dikes are consistent with lateral spreading that 

results from earthquake-induced liquefaction.

The morphology of the dikes in the Wabash Valley also 

presents evidence against nonseismic artesian pressures 

as the causal mechanism. Significant nonseismic artesian 

pressures should cause venting at isolated spots rather 

than venting as long, linear, parallel features; that this 

manifestation of venting at isolated spots should be 

expected is demonstrated by the formation of sand boils 

(a sand boil is a nonseismically induced feature) near the 

levees of the lower Mississippi River, from Cairo, 111., 

southward. Kolb (1976) has described the effects of 

flooding and the resulting artesian pressures beneath 

levees in the area. During high flooding, when artesian 

pressures are significant, features form that are 

described as "pin boils" and "pot holes." Kolb describes 

pot holes as large as 2 m in diameter and 1 m deep. 

Personnel at the U.S. Army Corps of Engineers, Memphis, Tenn. (written commun., 1989), have excavated 

into one of these artesian-induced pot holes and found 

that horizontal bedding extended well down into the 

throat, much below the original ground surface. This 

bedding apparently formed as sand and organic sediment 

fell into the open crater. If significant localized artesian 

pressures had been commonplace in the Wabash Valley, 

we would expect to see many of the same sorts of filled 

craters. We have found no filled craters; therefore, an

absence of high artesian conditions through the Holocene 

is strongly indicated.

The sand boils along the Mississippi River originated 

from water flowing through crayfish holes and root holes, 

according to Kolb (1976). Great numbers of vertical, 

tubular crayfish burrows are also present in the Wabash 

Valley, which should have allowed formation of springinduced sand boils if artesian pressures had been 

present. We have observed several tubular dikes filled 

with clean sand in the Wabash Valley, but only in very 

low swamps. We have found no tubular dikes that 

approach being filled with clean or silty sand or gravelly 

sand in the general vicinity of the planar dikes in the 

Wabash Valley. Therefore, we conclude that only insignificant artesian pressures through time could have 

contributed to formation of the dikes and that the 

maximum artesian pressures present in the vicinity of 

the dikes could not have approached a pressure head 

equal to the vertical effective stress applied by the 

low-permeability cap.

ROLE OF TOPOGRAPHY AND GEOLOGY ON GROUND-WATER CONDITIONS

We have also considered the possibility that significant 

artesian pressures originated from entrapment of water 

beneath the fine-grained cap as the ground water flowed 

from elevated areas. We feel that this possibility can be 

eliminated at many sites. The situations at Site PB (in 

point-bar deposits) and Site GR (in braid-bar deposits) 

are illustrative. These sites have nearby entrenched 

stream valleys or abandoned channels nearby that should 

have bled off any significant artesian pressures. The caps 

are also so thin and silty at these sites that seepage 

through the caps, as the water moved downslope, probably would not have permitted significant buildup of 

artesian pressure. A more detailed description of each of 

these two sites follows.

Figure 9 shows an aerial photograph, topographic 

map, and vertical section along a portion of the Wabash 

River banks where the Site PB dikes are present. These 

dikes have been bracketed as having formed between 1.5 

and 7.5 ka (this is the site shown as fig. 2 in Obermeier 

and others, 1991). We do not know if the dikes formed 

when the Wabash River occupied the meander loop north

FIGURE 7. —Vertical aerial photograph of a portion of the Manila, ^ 

Ark., 7.5-minute orthophotographic quadrangle. The photograph 

shows long fissures through which sand vented (light-colored linear 

features) and also shows individual sand blows (light-colored spots) 

formed by liquefaction during the 1811-12 New Madrid earthquakes. 

These features formed in latest Pleistocene braid-bar deposits and 

younger Holocene point-bar sediments. Note how fissures formed 

parallel to the scrolls of point-bar deposits.
ORIGIN OF FEATURES 11

1 MILE

J

1 KILOMETER

ARKANSAS

Location
12 HOLOCENE EARTHQUAKES IN THE WABASH VALLEY OF SOUTHERN INDIANA AND ILLINOIS

87°35'25"

Location and 

rorientatio 

:"of dikes

MILE

1 KILOMETER

B

FIGURE 8. —Aerial photograph (A) and topographic map (B) of Site VW 

(southwest of Vincennes, Ind.), and photographs (C and D) of the 

widest dike at the sites. Aerial photograph shows meander scrolls of 

point-bar deposits. The topographic map (a portion of USGS Vincennes, Ind.-Ill., 7.5-minute quadrangle, 10-ft contour interval) 

shows locations and strikes of dikes. Observed lengths of dikes have 

been exaggerated to illustrate the trend clearly; meander scrolls are 

indicated by dashed lines. Note that the dikes form a 350-m-wide 

zone that parallels the scrolls of point-bar deposits; these deposits are 

similar to those associated with the 1811-12 New Madrid earthquakes (fig. 7). C shows an oblique view of the streambank and a 

straight-on view of a 75-cm-wide dike. D shows a perpendicular view 

of the bank and an oblique view of the dike. (Scale is in meters.)

of the present river or if they formed after neck cutoff of 

that meander, when the river might have been 1 to 3 km 

to the south. What is known is that the dikes cut through 

point-bar deposits that were formed during the migration of the paleomeander that lies east, west, and north 

of the dikes; therefore, whatever the position of the 

Wabash River when the dikes formed, any significant 

artesian pressures from the terrace located to the east, 

west, and north would have been intersected by either an 

active river channel or a deep slough (fig. 9C).

FIGURE 8.—Continued.

If the Wabash River had been south of the dikes at the 

time of their formation, then its channel would have 

intersected any significant artesian pressures from that 

direction. Even if the river had been north of the dikes, 

the elevations of the valley surface for as far as 6 km to 

the south of the dikes are less than 2 m higher (elevation 

385 ft, 117 m) than the surface onto which the dikes 

vented (elevation about 380 ft, 116 m). This minor 

difference does not support an argument for significant 

artesian pressures from the south.

The only possible source of artesian pressure for the 

Site PB dikes would have been at the central portion 

(present northern extremity) of Peankishaw Bend, about 

1 km northwest of the dikes, where the laterally equivalent paleosol onto which the sand blow was vented (fig. 

9C) is about 1 to 2 m higher. Field evidence at the site 

suggests very strong flow forces. The width of the 

largest dike at this site exceeds 0.5 m throughout the 

height of the dike, which exceeds 3 m, and pebbly sand 

was vented onto a now-buried surface. Within the lower
ORIGIN OF FEATURES 13

FIGURE 8.—Continued.

FIGURE 8.—Continued.
14 HOLOCENE EARTHQUAKES IN THE WABASH VALLEY OF SOUTHERN INDIANA AND ILLINOIS

87°53'49"

FIGURE 9. —Aerial photograph, topographic map, and vertical section 

of location and geologic setting of dikes at Site PB, Wabash County, 

111. The aerial photograph (A) shows meander scrolls of point-bar 

deposits in which dikes formed. The topographic map (B) (a portion 

of USGS Grayville, Ill.-Ind., 7.5-minute quadrangle, 10-ft contour 

interval) shows location and strike of largest dikes (as much as 0.6 m 

wide) at the site and the location of a braid-bar terrace; lengths of 

dikes are exaggerated. The vertical section (C) shows location and 

elevation of paleosols, point-bar sediments, dikes, and sand blows 

that are exposed in river bank. Note orientation of point bars in 

paleomeander (A) and the same orientation of dikes in B.

half of the dike are many large gravels. It seems unreasonable to us that a vertical planar dike having such a 

large width could transport large gravels (up to 2 cm in 

diameter) upward in a field setting in which artesian 

pressures are not significant.

We now examine the setting at Site GR, which is about 

10 km south of Site PB. (This is the same Site GR 

described by Obermeier and others, 1991). Figure 10 

shows an aerial photograph, a topographic map, and a 

plan view map with locations and the strike of dikes (up 

to 30 cm wide) exposed in an open sand and gravel pit. 

The dikes cut through a 1.5- to 2-m-thick sandy and 

clayey silt cap that sharply overlies gravelly sand (braidbar deposits). Most likely, some of the dikes on the north

B

0 1 KILOMETER 

FIGURE 9.—Continued.

and west walls were connected before the pit was 

excavated. The gravelly sand beneath the fine-grained 

cap extends at least 8 m beneath the base of the 

fine-grained cap, on the basis of three engineering borings around the pit. Thickness of gravelly sand and sand 

exceeds 20 m throughout the region, according to the pit 

operators and highway department boring logs taken 

about 300 m from the pit. Soil development in dike 

fillings compared with undisturbed adjacent soil shows 

that the Site GR dikes postdate terrace formation, all 

overbank deposition, and most Holocene soil development. Therefore, the dikes considerably postdate initial 

formation of the braid-bar surface.

Various possible ground-water conditions at the site 

are relevant in regard to possible artesian pressure. 

High artesian pressures could not have originated from a 

source west of the pit, because point-bar scrolls clearly 

show that the Wabash River has continuously occupied 

that region. South and east of the pit is the Black River, 

which extends to the northeast from the area shown on 

the maps; this river should have bled off any significant 

artesian pressures originating in the terrace deposits and
ORIGIN OF FEATURES 15

METERS FEET 

5 >15

10

Modern surface

A'

-5

50 100 150 FEET

Sand and 

gravel dikes

FIGURE 9—Continued.

uplands to the northeast. The only source region for such 

artesian pressure would have been along the base of the 

bedrock hill, north of the town of Griffin and about 1.5 

km north of the features. The confining clayey silt cap is 

so thin throughout this region, however, that any 

buildup of significant pressures seems unlikely.

Not shown on figure 10C is a slight swale (approximately 100 m wide) that is filled with approximately 2 to 

3 m of gleyed clay (southwestward projection of swale is 

shown in fig. 105). Also not shown are small, vertical, 

planar sand-filled dikes about 100 m east of and parallel 

to the swale; thus, northeasterly oriented dikes are 

present both east and west of the swale. We do not know 

if a small stream occupied the swale at the time of 

formation of the dikes. However, if a stream occupied the 

swale, then the stream would have intersected artesian 

pressures from the north and precluded artesian-induced 

formation of the sand dikes on the west side of the swale. 

If a stream did not occupy the swale, then the dikes 

(parallel to both the course of Black River and to local 

relief) would have formed at least 1 km from the banks of 

the Black River. Horizontal block movements required 

to have formed the sand-filled fissures, at such a large 

distance on nearly flat ground and far from any stream 

banks, are best explained as a result of seismically 

induced liquefaction.

We emphasize that there are many more such sites 

where it can be shown that significant artesian pressures 

were very unlikely as a factor in forming the dikes. Sites 

PB and GR were chosen largely because of their ease of 

access to anyone interested in doing field examinations of 

the dikes.

NONSEISMIC LANDSLIDING

To determine whether nonseismically induced landslides could have formed the sand-filled dikes, we have

considered historical accounts of regional landslide 

behavior, particularly along the Wabash, Ohio, and Mississippi Rivers, in addition to accounts of worldwide 

landslide behavior and engineering mechanics of landsliding.

Landslide experience in the lower Mississippi River 

valley is summarized by Obermeier and others (1990, p. 

27):

Long irregular fissures through which sand has vented [similar to 

fissure pattern shown on fig. 7 in this paper] . . . have not been 

observed to have originated by springs in the alluvial lowlands of the 

St. Francis Basin [this basin occupies the region along the Mississippi 

River between Cairo, 111., and Memphis, Tenn.]. Slumps and lateral 

spreads along rivers (generally caused by rapid hydraulic drawdown 

after floods) can generate fissures, but we have not observed sand 

flowing to the surface through the fissures except for small amounts 

associated with water oozing through the slide mass. In addition, 

(nonseismic) lateral spreads and slumps that we have observed do not 

extend back from banks along large rivers more than 50 m. Thus we 

believe that fissures associated with vented sand that are located more 

than 50 m from present or former banks of rivers can generally be 

attributed to seismically induced slope instability. Confidence in this 

interpretation increases with increasing width of the sand-filled fissure 

and with increasing distance from the banks. In order to confidently 

attribute an earthquake mechanism to a specific vented-sand fissure, 

however, the location of the river at the time of fissure formation must 

be established, an undertaking that may be quite difficult.

The 50-m distance was provided by Mr. J. E. Monroe, 

one of the co-authors in Obermeier and others (1990), and 

was intended to be a conservative (large) distance from 

the head to the toe of the landslide. In addition, this 

distance was intended mainly for thinly interbedded 

sands and clays, where artesian pressures can be present 

locally during periods of rapid drawdown of the river. 

Sliding block failures in response to rapid drawdown of
16 HOLOCENE EARTHQUAKES IN THE WABASH VALLEY OF SOUTHERN INDIANA AND ILLINOIS

87°53'56"

' •£ : /

' Modern pit

FIGURE 10. —Aerial photograph, topographic map, and plan view of pit B 

showing location of dikes in Site GR, Posey County, Ind. The aerial 

photograph (A) shows the braid-bar terrace surface, the meander 

scrolls of point-bar deposits, and the bedrock (sandstone and shale) 

upland. The topographic map (B) (a portion of USGS New Harmony, 

Ind.-111., 7.5-minute quadrangle, 10-ft contour interval) shows locations of braid-bar deposits, point-bar deposits, the region of the pit 

that has numerous dikes, and the map in C. The plan view of the 

corner of the pit (C) shows the location and strike of dikes in the pit 

wall. Note northeast-southwest orientation of braid bars on the 

terrace, northeast-southwest orientation of the Black River, and the 

same orientation of dikes.

the river are reported to be fairly common along the Ohio 

River (Springer and others, 1985), but here, too, the 

failure zones are in very thin sand layers bounded above 

and below by low-permeability materials. Springer and 

others (1985) made a comprehensive study of streambank stability in the Ohio River system and noted that 

large slumps are a common type of failure, but they make 

no mention of lateral spreading on thick, clean sand 

deposits.

Some scattered landslides in the study area are initiated by shear failure that takes place on or through 

softened Pennsylvanian-age shales that underlie the allu0 1 KILOMETER 

FIGURE 10—Continued.

vium in the river valleys. These shales have minimum 

shear-strength (residual) angles that can be as low as 7° 

to 8° (Mesri and Gibala, 1971). At places where the 

shale-alluvium interface is only gently dipping, a sliding 

block can move toward a stream, especially where the 

bank is being undercut and when the stream level drops 

rapidly. An example of such a failure along the Ohio 

River near the confluence with the Wabash River has 

been studied extensively by Mundell and Warder (1984). 

Here, block movement, which perhaps began prehistorically, has shown horizontal displacement of a distance of 

1.5 to 2 m over a period of 20 years. The block extends 

about 50 m back from the river. Relatively slow movement taking place within 50 m of the river's edge seems 

to be the normal mode of failure of sliding on (or through) 

the shale throughout the Wabash Valley area (J.A. 

Mundell, Geotechnical engineer, ATEC Corp., Indianapolis, Ind., oral commun., 1991). Such a scenario of a 

slowly moving sliding block does not explain our observation that at many Wabash Valley sites, on virtually 

level ground far from steep slopes, there are sand- and
ORIGIN OF FEATURES 17

Strikes of vertical planar dikes 

exposed in pit walls

Open sand

and 

gravel pit

100

I_

150 FEET

_I

25

1

50 METERS

FIGURE 10.—Continued.

gravel-filled dikes. The static-failure sliding block mechanism does not seem to us to provide a means whereby 

large quantities of sand, and especially relatively clean 

gravel, could be transported vertically up the dikes as 

much as 3 to 5 m and then be vented onto the ground 

surface.

Both our field observations and our engineering borings in the Wabash Valley show a correlation between 

dike width and dike filling. The source zones for the 

widest dikes generally contain medium sand with little or 

no gravel, whereas nearby, much narrower dikes commonly have gravel-rich source zones. If the origin of the 

dikes were a statically induced sliding block, there should 

be no relation between dike width and dike filling. This 

relation between dike width and dike filling is best 

explained by an earthquake-induced liquefaction origin. 

(A gravelly sand doubtlessly is generally more difficult to 

liquefy and cause to flow than a clean sand because of 

large differences in permeability and large differences in 

the threshold flow velocity required to transport sediment.)

We have also considered the mechanism of statically 

induced liquefaction for the dikes. Static liquefaction may 

be responsible for causing large lateral spreads that 

initiate by failure of sensitive (or "quick") clays, such as 

has occurred in Scandinavia and in the St. Lawrence 

Valley. We are not aware of any accounts in the literature of static subaerial liquefaction on virtually level 

ground causing large lateral spreads by failure in thick, 

clean sands, or gravelly sands. In addition, senior geotechnical engineers at the Norwegian Technical Institute

(T. Loken, oral commun., 1991) and at the Swedish 

Geotechnical Institute (C.L. Viberg, oral commun., 

1991) are unaware of any such failures in Scandinavia. 

However, subaqueous slumps and mudflows appear to 

have been induced by spontaneous liquefaction on very 

gentle slopes in Scandinavia and elsewhere around the 

world (Andersen and Bjerrum, 1968); a characteristic 

common to all these slides is that failure originated in 

uniformly graded fine sands and coarse silts, with both 

having extremely high porosities. In the Wabash Valley, 

by comparison, our data show that liquefaction originated in sediments much denser, more well graded, and 

much coarser than the sediments that experienced spontaneous liquefaction.

If the dikes in the Wabash Valley had been caused by 

slumping, then strata should be vertically displaced. 

Vertical displacement across a dike has been observed at 

only two of the Wabash Valley sites, and this was small.

If the dikes in the Wabash Valley were caused by 

nonseismic landsliding, we would also expect to see many 

dikes in the Ohio Valley because of similar physical and 

geologic settings in the two valleys. As figure 1 shows, 

we searched many kilometers of outcrop in the Ohio 

Valley in proximity to the Wabash Valley, and we found 

only two small dikes, which were at a single site (SH).

In summary, we conclude that the model of nonseismic 

landsliding as the source of the linear dikes in the 

Wabash Valley is not supported by the field evidence.

SUDDEN LOWERING OF RIVER LEVEL

We have also considered sudden lowering of the level 

of the Wabash River as a possible source for residual 

pore-water pressures that could have formed the dikes. 

As noted previously, we suspect that most, if not all, of 

the dikes formed at the same time. The only mechanism 

that we can postulate to have caused a sudden lowering 

would be rupture of a huge icejam or logjam or a sudden 

change in river course. None of these mechanisms can 

explain the wide distribution and sizes of dikes that we 

have found. The dike distribution (fig. 1) shows a 35-kmwide core region with dikes having widths exceeding 60 

cm, and these are bordered regionally by smaller dikes. 

Sudden changes in water level at a point source along the 

river could not produce such a pattern far up and down 

the Wabash River. Sudden withdrawal of floodwaters 

also has been eliminated as a source mechanism, because 

residual excess pore-water pressure would not remain 

after drainage of surface floodwaters.

SYNDEPOSITIONAL PROCESSES, WEATHERING, AND 

FROST

Syndepositional processes in many sedimentary environments create large flow structures and intrusions, so
18 HOLOCENE EARTHQUAKES IN THE WABASH VALLEY OF SOUTHERN INDIANA AND ILLINOIS

early in the study we made a special effort to investigate 

the possibility of this mechanism as a source for the 

dikes. We eliminated syndepositional processes as the 

origin for some dikes because they cleanly cut (make 

brittle breaks) across sediment much younger than the 

source sands, and other dikes cut through very thick, 

highly plastic clay that accumulated slowly in a swamp 

environment. In addition, many of the source beds are 

thick, highly permeable sands, gravelly sands, or sandy 

gravels that would drain rapidly and thereby eliminate 

the possibility of pore-water pressure buildup caused by 

deposition of overlying sediments.

Weathering by chemical processes has produced karstlike development in calcareous outwash deposits in the 

Ohio River valley (Carroll, 1979). These weathered features are more or less tubular in plan view. We have 

observed what may be features caused by the same 

process in braid-bar deposits along some of the older, 

higher terraces in the Wabash Valley. The karstlike 

weathering features reported by Carroll and observed 

by us do not resemble the dikes in the Wabash Valley.

We have also considered the possibility that the dikes 

could have been produced by frost action. A report by 

Johnson (1990) summarizes the characteristics of frostrelated features in an area near our field study and points 

out that sediment is transported downward in frost 

features, in contrast to the evidence of upward movement of sediment that we have observed in the dikes. In 

addition, many or all of the dikes formed sometime 

between 1.5 and 7.5 ka, and this time period greatly 

postdates the period of significant frost action in the 

region.

PALEOSEISMIC IMPLICATIONS

SOURCE REGION

Consideration of dike sizes and distribution throughout the Wabash and Ohio Valleys, in conjunction with the 

regional geologic setting and seismic record, indicates 

that the tectonic source zone almost certainly is located 

in the Wabash Valley. The regional distribution of the 

dikes, the location of the largest dikes in the lower and 

central Wabash Valley, and the presence of only scattered small dikes in the Ohio Valley show that the New 

Madrid earthquake region, about 200 to 250 km to the 

southwest, could not have been the source for the 

Wabash Valley features. Further support for this interpretation is provided because extensive paleoliquefaction 

studies by Wesnousky and Leffler (1992) in the 1811-12 

New Madrid earthquakes' meizoseismal region have not 

detected any evidence of a very large earthquake during 

the past 5,000 to 10,000 years. Our search of about 20 km

of stream banks in the lowermost Ohio River valley and 

lowermost Tennessee River valley (fig. 1), in sediments 

of early Holocene age at many places, also revealed no 

evidence of exceptionally strong prehistoric shaking. We 

know of no reason to suspect exceptionally high or 

exceptionally variable amplification of bedrock accelerations that might explain how an earthquake outside the 

Wabash Valley could cause this concentration of large 

features in southeastern Illinois and southwestern Indiana. On a regional basis, the liquefaction susceptibility 

does not vary greatly throughout the major river valleys, 

because moderately to highly susceptible sands are widespread, water tables are high, and the range of alluvium 

thicknesses is similar (although almost certainly a 30-m 

thickness of alluvium experiences significant amplification of bedrock motions, as we discuss later). Consequently, on the basis of size and distribution of liquefaction features, we strongly suspect that the source region 

for the strongest earthquake(s) was in the general vicinity of Vincennes, Ind.

The apparent increase in size of liquefaction features 

along the White River from west to east might suggest 

another earthquake source far to the east of our lower or 

central Wabash River source zone. However, we suspect 

that this inverse pattern is due to lack of adequate 

outcrop (Munson and others, 1992) or could be due to 

variations in ground shaking caused by factors such as 

varying thicknesses and properties of alluvium. Further 

studies, particularly along the Embarras and White 

Rivers, are needed to resolve this question.

STRENGTH OF EARTHQUAKE(S)

A basis for placing limits on the strength of the 

paleoearthquake is provided by relating the areal distribution and size of liquefaction features in the Wabash 

Valley to those of historic earthquakes elsewhere in 

central and eastern North America. We make such a 

comparison with three historic earthquakes: the 1811-12 

New Madrid earthquakes, the 1895 earthquake of 

Charleston, Mo., and the 1886 earthquake of Charleston, 

S.C. The recent 1988 earthquake in Saguenay, Quebec, 

induced liquefaction but had a focal depth, stress drop, 

and shaking characteristics that are not believed typical 

of intraplate earthquakes of the Central and Eastern 

United States (Boore and Atkinson, 1992); therefore, we 

make no comparison with the liquefaction effects of that 

event. Our evaluation uses the moment magnitude values most commonly used by the seismological community 

for historic, preinstrumental earthquakes, although 

some recent studies suggest that these magnitude estimates possibly are too large (Bollinger, 1992; Hanks and 

Johnston, 1992). For now, we assume that the dikes were 

produced by a typical intraplate earthquake.
PALEOSEISMIC IMPLICATIONS 19

Liquefaction is produced mainly by upward propagation of shear waves from bedrock to the ground surface, 

and so any estimate of earthquake magnitude must 

account for (1) bedrock motions and their amplification in 

unconsolidated or soft sediments above bedrock and (2) 

liquefaction susceptibility. After these have been 

accounted for, the span and sizes of liquefaction features 

can be calibrated to magnitude by two methods: (1) the 

Liquefaction Severity Index method (LSI of Youd and 

Perkins, 1987; Youd and others, 1989) and (2) scaling to 

the outer limit of sand blows (Youd, 1991). The LSI 

method is a measure of horizontal displacement caused 

by lateral spreading as a function of distance from the 

epicenter and is based on lateral spread movement being 

largest where earthquake shaking is strongest, other 

factors being equal. The technique of scaling to the outer 

limits of sand blows is simply a comparison of the spans 

of sand-blow development.

Sufficient data are available in the Wabash Valley to 

place lower bounds on the areal distribution of sand 

blows and lateral spread displacements. The north-south 

distance over which we have discovered sand blows 

(from Sites OC to MA) from what we suspect to be a 

single earthquake is at least 175 km (the sand blows at 

Site OC are not small, so the span is larger), and the 

east-west span (from Sites NT I to AL) is at least 105 

km. Near the central part of the span of sand blows is the 

region of largest dikes, where dikes are as wide as 0.7 to 

2.5 m. Vertically planar dikes having widths exceeding 

15 cm throughout the height of the dike occur from Sites 

OC to BR, some 160 km apart. Actual maximum horizontal displacement at a Wabash Valley site probably 

exceeds a single dike width because (1) it is very likely 

that we did not always observe the single largest dike in 

the vicinity of a given site (dike width is largely affected 

by proximity to stream banks, and some of our liquefaction sites were probably far from streams) and (2) almost 

all sites having a large dike have numerous parallel 

smaller dikes nearby, so the total horizontal movement 

might be more closely approximated by the sum of dike 

widths. Alternatively, it can be argued that the dikes 

were widened in large part by sand and gravel abrading 

the clay-rich sidewalls, but that process does not explain 

the observation that the widths of large dikes are nearly 

constant in plan view and that sidewalls are often vertically parallel.

Liquefaction susceptibility of sand is closely related to 

the Standard Penetration Test (SPT) blow-count number 

(a common geotechnical engineering test), which is 

largely a measure of grain packing. A greater than 1 m 

thickness of loose sand deposit at a shallow depth (2 to 10 

m), located where the water table is within a few meters 

of the ground surface, is generally highly susceptible to 

liquefaction and to formation of dikes and sand blows. In

the Wabash Valley, our limited data show that loose 

sands having blow counts as low as 6 and 7 are sufficiently abundant to have a major influence on the 

regional pattern of sand-blow development. Blow counts 

of 4 or less appear to be rare. At several widely scattered 

paleoliquefaction sites in the Wabash Valley, the water 

table appears to have been within 2 m of the ground 

surface at the time of the earthquake, because the water 

table was probably at least as high as the bottoms of the 

dikes when they formed. Therefore, we suspect that the 

liquefaction susceptibility was relatively high at many 

places when the dikes formed but not as high as sands in 

other sedimentary environments. (Sands having considerably lower blow counts, and therefore higher susceptibility, are common in beach-dune complexes such as 

those of coastal South Carolina.)

At Wabash Valley liquefaction sites, the uppermost 

bedrock is nearly flat-lying, thick, Pennsylvanian indurated shale and sandstone. Thickness of flat-lying sedimentary rocks above Precambrian igneous rocks is about 

3,000 to 4,000 m (Bushbach and Kolata, 1990). Sand and 

gravel usually less than 30 m thick lies on bedrock. We 

have used a stochastic simulation (using the method of 

Boore, 1983) of bedrock accelerations and have estimated 

the amplification of these accelerations in the upper part 

of the sand and gravel column by using the linear 

propagation model in the program RATTLE, which considers vertical propagation of surface waves. (Our calculations are based on an Mw 6.5 event. Results for 

frequencies greater than 0.5 Hz are unaffected by magnitude; therefore, the actual magnitude is of very minor 

importance for our purpose.) A stress-drop value of 100 

bars has been used in accordance with the recommendation by Boore and Joyner (1991). Amplification in the soil 

column is estimated for three quality factor (Q) values 

(10, 15, and 20), which are thought to encompass the 

range of reasonable values. Table 1 shows the input 

parameters. Table 1 also lists the ranges and average 

values of peak and root-mean-square (rms) amplification 

of bedrock accelerations for the six random number seeds 

(stochastic simulations). An amplification between 2 and 

3 is shown to be most likely.

We have also used the nonlinear program SHAKE (see 

table 3) to estimate how much the stochastic peak 

acceleration in bedrock is amplified in the soil column. 

(Representative shear-wave velocity data were provided 

by D.L. Eggert of the Indiana Geological Survey and 

W.R. Eckhoff of Ball State University.) For the SHAKE 

analysis, the frequency range was restricted to a maximum value of 25 Hz, because higher frequencies in soil 

generally transmit a relatively small amount of energy. 

We initially estimated a damping factor of 10 percent for 

the soil column, but the procedure in SHAKE for ensuring strain compatibility reduced the damping values to
20 HOLOCENE EARTHQUAKES IN THE WABASH VALLEY OF SOUTHERN INDIANA AND ILLINOIS

TABLE 1.—RATTLE results for amplification of horizontal acceleration in soil with respect to bedrock in the Wabash Valley

[Mw = 6.5, hypocentral distance = 15 km, frequency band = 0.05-50 Hz, A cr = 

100 bars; bedrock t* (traveltime divided by Q for near-surface bedrock) = 0.01]

Material properties

Stratum 

and depth (m)

Sand, 0-10. .....

Sand, 10-30 .....

Bedrock, >30 . . .

Density 

(g/cm3)

2.0

2.0

2.5

Shear-wave 

velocity (m/s)

150 

300 

3,000

Quality 

factor (Q)

10, 15, 20 

10, 15, 20 

2,000

Amplification factors obtained by using 6 random number seeds 

for each Q value

Q (sand)

10 ..........

15 ..........

20 ..........

Peak

acceleration

amplification

ratio

. ... 1.9-2.9 (avg. = 2.1)

. . . . 2.0-3.5 (avg. - 2.4)

. . . . 2.2-3.9 (avg. = 2.7)

rms

acceleration

amplification

ratio

2.0-2.6 (avg. = 2.3)

2.4-2.9 (avg. = 2.6)

2.6-3.2 (avg. = 2.9)

generally less than 3 percent. The amplifications have 

been calculated by selecting two peak threshold accelerations at the surface, where small liquefaction features 

should be formed (we are concerned only with formation 

of small liquefaction features at the outer limits of the 

span of liquefaction features), and then calculating the 

associated bedrock accelerations. The input bedrock 

motions, based on six random time series, were the same 

set used in the RATTLE analysis (linear propagation). 

Surficial peak accelerations of 0.08 g and 0.10 g were 

used. Table 3 shows that the ratio is essentially insensitive to these acceleration values and to the procedure, 

and an amplification of about 2 is indicated. A similar 

analysis showed that the RATTLE and SHAKE procedures are not very sensitive to the range of shear-wave 

velocity and shear modulus values that are reasonably 

possible in sandy alluvium.

We now compare Wabash Valley liquefaction effects 

with those elsewhere. The areal distribution of sand 

blows induced by the four strongest New Madrid earthquakes (mb~7.0 to 7.4, Mw ~7.8 to 8.3; Nuttli, 1979; 

Johnston, 1992) is very poorly known, but the maximum 

span of liquefaction features for the strongest of those 

earthquakes (mb~7.4, Mw~8.3) certainly far exceeds 

what we have found in the Wabash Valley. The span for 

what we presume to have been caused by the strongest 

earthquake (Mw~8.3, on Feb. 7, 1812) appears to have 

been on the order of 500 km. This distance is based on 

observations of sand blows on the flood plain of the 

Mississippi River near St. Louis, Mo., and also in the 

lowermost Wabash Valley (Youd and others, 1989). We 

believe it likely that liquefaction susceptibility and bedrock amplification were relatively comparable at and

TABLE 2. —RATTLE results for amplification of horizontal acceleration in soil with respect to bedrock near Charleston, Mo.

[Mw = 6.5, hypocentral distance = 15 km, frequency band = 0.05-50 Hz, A cr 

= 100 bars, bedrock t* (traveltime Q for near-surface bedrock) = 0.01]

Material properties

Stratum 

and depth (m)

Sand, 0-10. ......

Sand, 10-38. .....

Sand and clay, 

38-148 .........

Sand and clay, 

148-258 ........

Bedrock, >258 . . .

Density 

(g/cm3 )

2.0 

2.0

2.0

2.0 

2.5

Shear-wave 

velocity (m/s)

150 

300

330

667 

3,000

Quality 

factor (Q)

10, 15, 

10, 15,

20

50 

2,000

20 

20

Amplification factors obtained by using 6 random number seeds 

for each Q value in the upper 38 m of sand

Q (sand) Peak acceleration 

amplification ratio

rms acceleration 

amplification ratio

10 .............. 1.2-1.9 (avg. = 1.5)

15 .............. 1.4-2.1 (avg. = 1.7)

20 .............. 1.5-2.2 (avg. = 1.8)

1.5-2.0 (avg. = 1.8) 

1.7-2.1 (avg. = 1.9) 

1.7-2.2 (avg. = 2.0)

near these two river valley sites during the 1811-12 and 

Wabash Valley earthquakes. Therefore, this comparison 

of spans suggests that the strongest 1811-12 earthquake 

far exceeded the magnitude of any earthquake that 

produced the liquefaction features in the Wabash Valley 

(see table 5).

The 1895 earthquake of Charleston, Mo. (mb~6.2, 

Mw~6.8; Nuttli, 1979; Johnston, 1992), located in the 

New Madrid seismic zone, is the only earthquake that is 

known to have produced sand blows in the Central 

United States since the 1811-12 New Madrid earthquakes. The diameter of the region of reported sand 

blows and minor liquefaction effects was about 16 km 

(Powell, 1975); Powell describes liquefaction effects 

mainly in the meizoseismal region and east and south of 

this region, so it is likely that some liquefaction sites to 

the north and west were not noted. Still, because the 

nearby Mississippi and Ohio Rivers are bordered with 

sediments highly susceptible to formation of sand blows, 

and because thousands of people were living along these 

rivers in 1895 (Cairo, 111., is about 15-20 km from the 

epicenter) and did not report liquefaction features, it is 

unlikely that the actual diameter of distribution of sand 

blows much exceeded twice the reported span of 16 km, 

or 32 km. Our preliminary investigations using the 

programs RATTLE (tables 1 and 2) and SHAKE (tables 3 

and 4) suggest that surface ground motions for an 

earthquake of given magnitude are amplified only 

slightly to moderately higher in the Wabash Valley 

relative to the 1895 Charleston earthquake epicentral 

region (table 5). Therefore, the large 175- by 105-km area
PALEOSEISMIC IMPLICATIONS 21

TABLE 3.— SHAKE results for amplification of horizontal acceleration 

in soil with respect to bedrock in the Wabash Valley 

[Mw = 6.5, maximum frequency = 25 Hz, A <r = 100 bars]

Material properties

Stratum and Density Shear-wave , , i 

, ,, , , / , s\. i -i. , i \ modulus depth (m) (g/cnr) velocity (m/s) ,, , 2^

Sand, 0-10 ........ 2.0 150 460

Sand, 10-30 ....... 2.0 300 1,835

Bedrock, >30 ..... 2.5 3,000

Amplification factors for 6 random number seeds, for peak 

acceleration at ground surface = 0.08 g

Peak Peak 

Seed no. acceleration acceleration Amplification 

at top of at ground ratio 

bedrock (g) surface (g)

1 0 047 0 080 1 7

2.............. .038 .083 2.2

3.............. .048 .085 1.8

4.............. .044 .085 1.9

5.............. .034 .078 2.3

6 MQ7 M7Q 9 1

average: 2.0

Amplification factors for 6 random number seeds, for peak

c, , Peak Peak Amplification Seed no. , , . , , . , . acceleration acceleration ratio

1.............. 0.047 0.100 2.1

2.............. .057 .098 1.7

3.............. .052 .098 1.9

4.............. .059 .095 1.6

5.............. .050 .106 2.1

6.............. .049 .098 2.0

average: 1.9

1Value for 10~4 % shear strain.

of sand blows in the Wabash Valley, combined with the 

presence of very large dikes in the core area, suggests 

that prehistoric shaking in the Wabash Valley greatly 

exceeded that of the 1895 Charleston earthquake. 

A rough comparison of liquefaction effects can also be 

made with the 1886 earthquake of Charleston, 

S.C.(mb~6.7, Mw ~7.5; Nuttli and others, 1979; 

Johnston, 1992), whose epicenter was near the ocean. 

The Charleston area is in the stable continental region 

and presumably for a given earthquake magnitude has 

similar source dimensions and bedrock shaking characteristics to a typical intraplate earthquake (A.C. 

Johnston, Memphis State Univ., oral commun., 1991). 

Observers at the time of the 1886 earthquake noted 

numerous liquefaction features, notably "craterlets," 

that formed in the 30- by 50-km meizoseismal region 

(Button, 1889). Button also reported that craterlets

TABLE 4.— SHAKE results for amplification of horizontal acceleration 

in soil with respect to bedrock near Charleston, Mo. 

[Mw = 6.5, maximum frequency = 25 Hz, A cr = 100 bars]

Material properties

Stratum and Density Shear-wave , , i 

, ,, , , / / 3x * •*. , i \ modulus depth (m) (g/cm ) velocity(m/s) ,, , 2)

Sand, 0-10. ...... 2.0 150 460

Sand, 10-38. ..... 2.0 300 1,835

Sand and clay, 

38-148 ......... 2.0 330 2,220

Sand and clay, 

148-258 ........ 2.0 667 9,065

Bedrock, >258 ... 2.5 3,000

Amplification factors for 6 random number seeds, for peak 

acceleration at ground surface = 0.08 g

Peak Peak

,-, , acceleration acceleration Amplification Seed no. , , „ , , , . at top of at ground ratio

bedrock (g) surface (g)

1 ............... 0.060 0.082 1.4

2 ............... .064 .083 1.3

3 ............... .086 .084 1.0

4 ............... .086 .084 1.0

5 ............... .074 .082 1.1

6

A/?Q (Y7R 1 1

average: 1.2

Amplification factors for 6 random number seeds, for peak 

acceleration at ground surface = 0.10 g

Peak Peak

,-, , acceleration acceleration Amplification Seed no. , , „ , , , . at top of at ground ratio

bedrock (g) surface (g)

1 ............... 0.081 0.104 1.3

2 ............... .084 .100 1.2

3 ............... .112 .098 .9

4 ............... .098 .103 1.1

5 ............... .100 .097 1.0

6 ............... .106 .098 .9

average: 1.1

1Value for 10~4 % shear strain.

formed over a region about 100 km in diameter centered 

about the epicenter. Widely scattered, much smaller 

craterlets and small sand-filled dikes may have formed 

much beyond the 100-km diameter. Very small, apparently liquefaction-induced features were reported up to 

100 km from the epicenter, northeastward along the 

coast (Youd and others, 1989). Very small features that 

appear to have an 1886 earthquake origin have been 

found by Obermeier (unpub. data, 1986) along the coast 

at a site about 100 km southwest of the epicenter, and 

medium-sized features have been reported at the same 

site by Amick and others (1990). No 1886-vintage lique-
22 HOLOCENE EARTHQUAKES IN THE WABASH VALLEY OF SOUTHERN INDIANA AND ILLINOIS

TABLE 5.—Comparison of liquefaction effects with factors controlling liquefaction for earthquakes in the Central and Eastern United States

Earthquake 

source

Wabash Valley

Maximum span 

of sand blows 

(diameter about 

epicenter)

>175 km

Maximum span for 

lateral spread movement of 0. 15 m

Probably >160 

km

A 

Liquefaction 

susceptibility

Locally high (SPT 

blow counts as 

low as 6-7)

B 

Amplification of bedrock 

acceleration

Likely moderate 

amplification (factor 

of 2-3 as per RATTLE, or 2 as per 

SHAKE)

^ u- j ft *. t Earthquake magm- Combmed effect of , . 

, „ , . tude relative to sm- A and B relative to 117 u v. Tr u £le Wabash Valley Wabash Valley paleoearthquake

New Madrid, 

Mo., Feb. 7, 1812 

(mb ~ 7.4, Mw 

-8.3)

Charleston, Mo., 

1895 (mb ~ 6.2, 

Mw~6.8)

Charleston, S.C., 

1886 (mb ~ 6.7, 

Mw~ 7.5)

Probably about 

500-550 km

Probably <40 km 

(16 km reported)

Probably on the 

order of 200-250 

km (100 km 

reported)

Locally high

Locally high, 

especially along 

rivers

Same as above along 

Mississippi and 

Wabash River valleys

About same along 

these valleys

Likely moderate ampli- Likely slightly 

fication (factor of to moderately 

1.5-2 as per RAT- higher 

TLE, or 1.15 as per 

SHAKE)

-140 km (calculated from Youd 

and others, 

1989)

Locally extremely Likely slight amplificahigh near coast tion or attenuation 

(SPT blow 

counts as low as 

0-2)

Likely slightly 

higher

Much higher

Much lower

Likely same 

order of magnitude

faction features have been found farther southwestward 

along the coast, despite extensive field searching. Therefore, along the coast the span of liquefaction features 

appears to be about 200 km or a little more. This span is 

very probably a maximum distance, because no liquefaction features were reported very far inland from the 

epicenter (away from the coast) despite the presence of 

extensive wet lowlands underlain by loose sands that are 

not far inland from the epicentral area. Because there 

has been no direct evidence of faulting found at the 

surface, the location of the 1886 earthquake fault remains 

controversial. The principal axis of the meizoseismal 

region, and presumably the major rupture for the 1886 

earthquake, was oriented about 30 degrees from the 

coast (Plate XXVII, Button, 1889). However, the lack of 

liquefaction features in fluvial sediments at large distances along the strike of the meizoseismal area indicates 

that the extent of liquefaction measured on the coast is 

not an underestimate caused by directivity or effects of 

the focal mechanism. Thus the extent of sand blows 

appears to be similar for the Wabash Valley and the 1886 

Charleston earthquakes.

The largest horizontal movement associated with a 

lateral spread in the 1886 Charleston earthquake epicentral region was 2.5 m (Youd and others, 1989), which is 

the same as the width of the largest dike that we have 

found in the Wabash Valley (at Site ER). The span of 

lateral spread movement for Charleston also appears 

comparable for movement of 15 cm (6 in). Youd and

others (1989), by interpreting historical accounts of liquefaction effects, have derived mathematical relations 

between lateral spread movements as a function of 

epicentral distance (LSI relations) for the 1886 Charleston earthquake and estimate a span of about 140 km for 

15-cm movements. In the Wabash Valley, movements of 

at least 15 cm appear to have taken place from Sites BR 

to OC, a span of 160 km.

In summary, both the criteria of span of sand blows 

and lateral spread movement show comparable liquefaction effects in the Wabash Valley with those of the 1886 

Charleston earthquake. Other factors to consider for 

evaluating magnitude are liquefaction susceptibility and 

amplification of bedrock shaking. The South Carolina 

coastline has abundant deposits that are extremely susceptible to liquefaction and flow. Martin and Clough 

(1990) found that 1-m-thick, uniformly sorted, fine sand 

deposits having blow counts of 2 or less, with the water 

table at the ground surface, are common near the coast. 

(In the Wabash Valley, sands are much more poorly 

sorted, and blow counts less than 6 are not common.) For 

loose sands (having blow counts less than about 10) there 

is an approximately linear, one-to-one relation between 

earthquake accelerations and blow count for initiation of 

liquefaction in loose sands (see, for example, fig. 4-68 in 

National Research Council, 1985). Thus the threshold 

acceleration is on the order of three or more times higher 

for Wabash Valley sands than for those in coastal South 

Carolina.
PALEOSEISMIC IMPLICATIONS

Near the epicentral regional (within 50 to 100 km), 

earthquake accelerations in coastal South Carolina were 

probably attenuated as they progressed upward from 

bedrock through the 1-km thickness of semilithified, 

pre-Quaternary Coastal Plain deposits, according to 

studies by Chapman and others (1990). They estimate 

that the peak acceleration at the base of Quaternary 

deposits is on the order of two-thirds the value of 

bedrock acceleration at an epicentral distance of 60 km 

and is proportionally higher with increasing distances. 

(Chapman and others used a 1-km thickness of Tertiary 

sediments along the coast; a quality (Q) value of 20 and 

shear-wave velocity of approximately 1 km/s were 

assigned to these deposits, with a stress-drop value of 

100 bars.) We believe that this Q value of 20 is too low for 

the Tertiary sediments; using a Q of 50 for these sediments suggests that there is only minor change between 

accelerations in bedrock and in the base of Quaternary 

deposits. Unpublished studies by Martin (1990) show 

that in the 10- to 20-m thickness of Quaternary deposits 

along the coast, accelerations from the underlying preQuaternary Coastal Plain sediments are changed either 

slightly or not at all. Overall, it appears that bedrock 

motions were not changed much at the ground surface 

along the coast at distances exceeding 50 km from the 

epicenter.

The combined factors of bedrock amplification (minor 

change in amplification or attenuation) and liquefaction 

susceptibility (extremely high) in coastal South Carolina, 

when compared to those that produce liquefaction features in the Wabash Valley (moderate to slight amplification and high liquefaction susceptibility), appear 

approximately equal for earthquakes of equal magnitudes. Therefore, relatively equal spans of sand blows 

and lateral spread movements in the two regions suggest 

that earthquake magnitudes were about the same.

We next make an estimate of the magnitude of the 

single Wabash Valley earthquake by using a graphical 

procedure for scaling to the outer bound of sand blows. A 

theoretical and philosophical basis for the technique 

developed by Youd and Perkins (1978) shows that a 

unique bound of liquefaction effects should exist for a 

given tectonic setting, if other factors are fixed. Data 

from the 1895 earthquake of Charleston, Mo., and the 

1811-12 New Madrid earthquakes, presented in figure 

11, are used for our analysis.

Figure 11 is a plot (modified from Ambraseys, 1988) 

comparing moment magnitude versus epicentral distance 

to the farthest liquefaction features; the bound by 

Ambraseys for shallow-focus earthquakes is shown also. 

According to Youd (1991, p. 129-130), the data apparently include all effects of liquefaction, including minor 

fissures and small sand blows, and "Ambraseys' points 

for intermediate depth earthquakes generally lie well

beyond the bounds for shallow-focus events, indicating 

that intermediate-depth earthquakes may generate liquefaction to larger distances than shallow events." Figure 11 contains data mostly from intraplate and crustal 

earthquakes in the Western United States and Japan but 

also includes data from areas of lower attenuation. The 

farthest distance to sand blows for the intermediatedepth 1988 Saguenay earthquake is seen to extend 

beyond Ambraseys' bound.

Figure 11 shows, in addition, the data points for the 

farthest reported sand blows of the 1811-12 earthquakes. These liquefaction features formed during the 

month of February, which is normally in the season when 

the water table is very high (and therefore most likely to 

produce sand blows), although we have no weather data 

for that time. Epicentral distances for the 1895 Charleston, Mo., earthquake are shown as 16 and 20 km. The 16- 

km distance represents what is thought to be an upper 

limit from the epicenter on the basis of reported effects. 

The 20-km distance is from the epicenter to the town of 

Cairo, 111., located along the banks of the Ohio River 

where no sand blows were reported, and therefore is an 

absolute upper limit.

We now address the relation of the 1895 Charleston, 

Mo., liquefaction data to the 1811-12 New Madrid liquefaction data and to the Wabash Valley liquefaction data. 

Wabash Valley seismicity tends to originate at a greater 

depth than does seismicity in the New Madrid seismic 

zone, but hypocentral depths of strongest earthquakes in 

both the New Madrid seismic zone and in the Wabash 

Valley are less than about 10 to 20 km (Gordon, 1988). On 

this basis, both areas qualify as sources for shallow-focus 

earthquakes. Regional stress fields (northeastsouthwest compression) and major fault zones are oriented similarly in the Wabash Valley and in the New 

Madrid seismic zones (W.L. Ellis, U.S. Geological Survey, oral commun., 1992), although locally there are 

significant variations in stress orientation. Therefore, it 

is reasonable to assume that earthquakes in both regions 

have similar shaking characteristics at the source and 

that liquefaction effects will be bound by the same line, 

providing that an accounting is made for the factors of 

amplification of bedrock motions and liquefaction susceptibility. Bedrock shaking is amplified less in the Charleston, Mo., area than in the Wabash Valley, according to 

our analyses made with the programs RATTLE and 

SHAKE (shaking is amplified less by factors of about 1.25 

and 1.7, respectively). Where farthest liquefaction takes 

place, bedrock shaking amplitude decays inversely proportional to distance from the earthquake source as a 

result of geometric spreading. Because of the high Q of 

the crust, anelastic and scattering losses are small over 

this distance. In the Wabash valley, an earthquake in the 

Wabash Valley of equivalent magnitude to the 1895
24 HOLOCENE EARTHQUAKES IN THE WABASH VALLEY OF SOUTHERN INDIANA AND ILLINOIS

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Epicentral distance (radius) to farthest liquefaction feature (km)

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EXPLANATION

• Farthest sand blows for 1895 Charleston, 

Mo., earthquake, corrected for bedrock 

amplification in Wabash Valley

Farthest sand blows for 1988 

Saguenay, Quebec, earthquake

Bound suggested by Ambraseys (1988)

Upper bounds for Wabash Valley when 

our analysis is used

Most reasonable bound for Wabash Valley 

when our analysis is used

FIGURE 11.—Relationship between earthquake moment magnitude (Mw) and distance from earthquake epicenter to the 

farthest liquefaction feature. (Modified from Ambraseys, 1988.)

Farthest liquefaction effects (sand 

blows, fissures, and such) for 

shallow-focus earthquakes

Farthest liquefaction effect for 

deep-focus earthquakes (>50 km)

Farthest sand blows reported for 

1811-12 New Madrid earthquakes

Farthest sand blows for 1895 

Charleston, Mo., earthquake
ACKNOWLEDGMENTS 25

Charleston, Mo., earthquake would cause equivalent 

shaking (and farthest liquefaction, for the condition of 

equal liquefaction susceptibilities) at epicentral distances

I.25 and 1.7 times greater (according to RATTLE and 

SHAKE, respectively) than it would around Charleston, 

Mo. In the Wabash Valley, the equivalent distance from 

the 1895 Charleston epicenter to Cairo, 111., is 25 km (20 

kmx 1.25, RATTLE analysis) and 34 km (20 kmx 1.7, 

SHAKE analysis). These data points are shown on figure

II.

We previously argued that the susceptibilities of the 

most liquefiable sediments are reasonably comparable in 

the Charleston, Mo., and Wabash Valley areas. The most 

susceptible sediments in both regions are recent river 

deposits. In addition to having similar depositional processes, the grain-size gradations of the most susceptible 

sediments are about the same, thicknesses of capping 

sediments are commonly comparable, and the water 

table is always very shallow at many places. Therefore, 

the susceptibility of the most liquefiable deposits is 

approximately the same for our purpose of evaluating the 

relations between earthquake magnitude and the span of 

sand blows.

The next concern is the shape of the line on figure 11 

connecting the corrected 1895 Charleston, Mo., earthquake data to the 1811-12 earthquake data point (the 

250-km distance). A straight line connecting the points 

probably represents an extreme upper limit. Most likely, 

the shape is similar to Ambraseys' bound. The straight 

line intersects the epicentral distance to the farthest 

Wabash Valley liquefaction sand blows (89 km) at 

moment magnitudes of 7.5 and 7.7. Curved lines yield 

moment magnitudes of about 7.4 to 7.5.

This graphical analysis leads us to the same conclusion 

that we arrived at by our comparison of the span and 

lateral spreading movements of Wabash Valley liquefaction features with those of the 1886 Charleston, S.C., 

earthquake: it is likely that an earthquake having a 

moment magnitude of about 7.5 struck the Wabash 

Valley. Thus, completely independent methods of evaluation yield the same result. We emphasize, though, that 

these estimates of magnitude assume a normal intraplate 

stress drop (100 bars) and typical focal depth (10 to 20 

km) and are therefore best viewed as tentative and 

subject to change with future studies.

CONCLUSIONS

1. The dikes in the Wabash Valley are interpreted to be 

of earthquake origin, on the basis of the following 

evidence.

a. The dikes have characteristics that are generally 

consistent with dikes produced by earthquakes elsewhere in a similar geologic setting and, in particular, 

with the meizoseismal region of the 1811-12 New 

Madrid earthquakes.

b. We have found no field evidence, of the sort that 

should be commonplace, to support nonseismic origins for dikes in the Wabash Valley, such as artesian 

conditions or landslides.

c. The field settings in which the dikes formed at 

almost all sites shown in figure 1 are not conducive 

to formation of significant artesian conditions that 

can induce nonseismic lateral spreading landslides, 

d. In addition, there are only rare, localized occurrences of small dikes in the Ohio River valley, just 

south of the lower Wabash Valley, and the ability to 

produce landslides and liquefaction features appears 

comparable in the Wabash and Ohio River valleys, 

e. Mechanisms such as sudden lowering of the river 

level, weathering, or frost action do not explain the 

characteristics and distribution of dikes in the 

Wabash Valley.

2. It is highly possible that virtually all the dikes were 

formed by a single large earthquake that took place 

between 1,500 and 7,500 years ago.

3. The epicenter of the strongest earthquake(s) 

appears to have been in the general vicinity of 

Vincennes, Ind.

4. The strength of earthquake shaking that formed the 

dikes in the Wabash Valley far exceeds historic 

levels of shaking in this area and far exceeds the 

level of shaking and magnitude of the 1895 Charleston, Mo., earthquake (mb~6.2, Mw~6.8).

5. If all the dikes in the Wabash Valley are from a 

single earthquake, the magnitude appears to have 

been on the order of that of the 1886 Charleston, 

S.C., earthquake (mb~6.7, Mw~7.5).

6. More field research should provide insight into the 

origin of the dikes, should clarify whether the liquefaction features are the result of a single earthquake 

or multiple events, and should provide a better 

estimate of the magnitude of the earthquake that is 

believed to have caused the features.

ACKNOWLEDGMENTS

This research was funded by the U.S. Nuclear Regulatory Commission and by the National Earthquake 

Hazards Reduction Program. We are indebted to Ned 

Bleuer of the Indiana Geological Survey for his assistance in field interpretations and to Wen-June Su and 

Leon Pollmer of the Illinois State Geological Survey for 

their assistance in fieldwork in Illinois. We also thank the 

many personnel at county offices of the Soil Conservation 

Service, U.S. Department of Agriculture, and the many
26 HOLOCENE EARTHQUAKES IN THE WABASH VALLEY OF SOUTHERN INDIANA AND ILLINOIS

property owners who permitted us access. Excellent 

reviews of the paper were made by Martitia Tuttle of 

Lamont-Doherty Geological Observatory of Columbia 

University, David Amick of EBASCO Corporation, and 

Steve Personius and David Perkins of the U.S. Geological Survey. Charles Mueller of the U.S. Geological 

Survey was kind enough to provide us the program 

RATTLE, which he wrote.

REFERENCES CITED

Ambraseys, N.N., 1988, Engineering seismology: Earthquake Engineering & Structural Dynamics, v. 17, no. 1, p. 1-105.

Amick, D., Gelinas, R., Maurath, G., Cannon, R., Moore, D., Billington, E., and Kemppinen, H., 1990, Paleoliquefaction features 

along the Atlantic seaboard: Washington, D.C., U.S. Nuclear 

Regulatory Commission, Report NUREG/CR-5613, 146 p.

Andersen, A., and Bjerrum, L., 1968, Slides in subaqueous slopes in 

loose sand and silt: Oslo, Norwegian Geotechnical Institute, Publication no. 81, p. 1-9.

Andrus, R.D., Stokoe, K.H., and Roesset, J.M., 1991, Liquefaction of 

gravelly soil at Pence Ranch during the 1983 Borah Peak, Idaho 

earthquake: Proceedings of the Fifth International Conference on 

Soil Dynamics and Earthquake Engineering, Karlsruhe, Germany, 

p. 251-262.

Bollinger, G.A., 1992, Relations between magnitude scales from measurements of U.S. earthquakes—Preliminary results, mU.S. Geological Survey, Review of earthquake hazard assessments of plant 

sites at Paducah, Kentucky, and Portsmouth, Ohio: Administrative Report to the Department of Energy, 249 p.

Boore, D.M., 1983, Stochastic simulation of high-frequency ground 

motions based on seismological models of the radiated spectra: 

Bulletin of the Seismological Society of America, v. 73, no. 6, p. 

1865-1894.

Boore, D.M.-, and Atkinson, G.M., 1992, Source spectra for the 1988 

Saguenay, Quebec, earthquakes: Bulletin of the Seismological 

Society of America, v. 82, no. 2, p. 683-719.

Boore, D.M., andJoyner, W.B., 1991, Estimation of ground motion at 

deep-soil sites in eastern North America: Bulletin of the Seismological Society of America, v. 81, no. 6, p. 2167-2185.

Bristol, H.M., and Treworgy, J.D., 1979, The Wabash Valley Fault 

System in southern Illinois: Illinois State Geological Survey Circular 509, 19 p.

Bushbach, T.C., and Kolata, D.R., 1990, Regional setting of Illinois 

Basin, in Leighton, M.W., Kolata, D.R., Oltz, D.F., and Eidel, 

J.J., eds., Interior cratonic basins: American Association of Petroleum Geologists Memoir 51, p. 29-55.

Carroll, M.T., 1979, A model for karst-like development in calcareous 

outwash deposits: Urbana, 111., University of Illinois, M.S. thesis, 

130 p.

Chapman, M.C., Bollinger, G.A., Sibol, M.S., and Stephenson, D.E., 

1990, The influence of the Coastal Plain sedimentary wedge on 

strong ground motions from the 1886 Charleston, South Carolina, 

earthquake: Earthquake Spectra, v. 6, no. 4, p. 617-640.

Dutton, C.E., 1889, The Charleston earthquake of August 31, 1886: 

U.S. Geological Survey Ninth Annual Report, p. 203-528.

Fuller, M.L., 1912, The New Madrid earthquake: U.S. Geological 

Survey Bulletin 494, 119 p.

Gordon, D.W., 1988, Revised instrumental hypocenters and correlation 

of earthquake locations and tectonics in the Central United States: 

U.S. Geological Survey Professional Paper 1364, 69 p.

Gray, H.H., and others, state compilations, and Richmond, G.M., and 

Fullerton, D.S., editing and integration, 1991, Quaternary geologic map of the Louisville 4°x6° quadrangle, United States: U.S. 

Geological Survey Miscellaneous Investigations Series Map 1-1420 

(NJ-16), scale 1:1,000,000.

Hamilton, R.M., and Johnston, A.C., eds., 1990, Tecumseh's prophecy—Preparing for the next New Madrid earthquake: U.S. Geological Survey Circular 1066, 30 p.

Hanks, T.C., and Johnston, A.C., 1992, Common features of the 

excitation and propagation of strong ground motion for North 

American earthquakes: Bulletin of the Seismological Society of 

America, v. 82, no. 1, p. 1-23.

Johnson, W.H., 1990, Ice-wedge casts and relict patterned ground in 

central Illinois and their environmental significance: Quaternary 

Research, v. 33, no. 1, p. 51-72.

Johnston, A.C., in press, The stable-continental-region earthquake 

data base, in Coppersmith, K.J., and others, eds., Methods for 

assessing maximum earthquakes in the central and eastern United 

States: Palo Alto, Calif., Electric Power Research Institute, 

Project RP-2556-12.

Kolb, C.R., 1976, Geologic control of sand boils along Mississippi River 

levees, in Coates, D.R., ed., Geomorphology and engineering: 

Stroudsburg, Pa., Dowden, Hutchinson & Ross, Inc., p. 99-114.

Kuribayashi, E., and Tatsuoka, F., 1975, Brief review of liquefaction 

during earthquakes in Japan: Soils and Foundations, Japanese 

Society of Soil Mechanics and Foundation Engineering, v. 15, no. 

4, p. 81-91.

Leffler, L.M., 1991, Paleoseismic study of the southern New Madrid 

seismic zone by using liquefaction features as seismic indications: 

Memphis, Tenn., Memphis State University, M.S. thesis, 142 p.

Martin, J.R., and Clough, G.W., 1990, Implications from a geotechnical 

investigation of liquefaction phenomena associated with seismic 

events in the Charleston, South Carolina area: Blacksburg, Va., 

Virginia Polytechnic Institute and State University, 414 p.

Mesri, G., and Gibala, R., 1971, Engineering properties of a Pennsylvanian shale: Proceedings of the 13th Symposium on Rock Mechanics, Urbana, 111., p. 57-75.

Mundell, J.A., and Warder, D.L. 1984, Geotechnical engineering 

investigation of slope instability, Phase I Study, Texaco Mount 

Vernon terminal, Mount Vernon, Ind.: Indianapolis, Ind., ATEC 

Associates Project No. 21-53201, 66 p.

Munson, P.J., Munson, C.A., Bleuer, N.K., and Labitzke, M.D., in 

press, Distribution and dating of prehistoric earthquake liquefaction in the Wabash Valley of the central U.S.: Seismological 

Research Letters, v. 63, no. 2.

National Research Council, 1985, Liquefaction of soils during earthquakes: Washington, D.C., National Academy Press, 240 p.

Nuttli, O.W., 1979, Seismicity of the central United States, in Reviews 

in Engineering Geology: Geological Society of America, v. 4, p. 

67-93.

Nuttli, O.W., Bollinger, G.A., and Griffiths, D.W., 1979, On the 

relation between Modified Mercalli intensity and body-wave magnitude: Bulletin of the Seismological Society of America, v. 69, no. 

3, p. 893-909.

Obermeier, S.F., 1989, The New Madrid earthquakes—An 

engineering-geologic interpretation of relict liquefaction features: 

U.S. Geological Survey Professional Paper 1336-B, 114 p.

Obermeier, S.F., Bleuer, N.K., Munson, C.A., Munson, P.J., Martin, 

W.S., Me Williams, K.M., Tabaczynski, D.A., Odum, J.K., Rubin, 

M., and Eggert, D.L., 1991, Evidence of strong earthquake 

shaking in the lower Wabash Valley from prehistoric liquefaction 

features: Science, v. 251, p. 1061-1063.

Obermeier, S.F., Jacobson, R.B., Smoot, J.P., Weems, R.E., Gohn, 

G.S., Monroe, J.E., and Powars, D.S., 1990, Earthquake-induced 

liquefaction features in the coastal setting of South Carolina and in
REFERENCES CITED 27

the fluvial setting of the New Madrid seismic zone: U.S. Geological

Survey Professional Paper 1504, 44 p. 

Powell, B.F., 1975, History of Mississippi County, Missouri, beginning

through 1972: Independence, Mo., BLN Library Service, 428 p. 

Saucier, R.T., 1989, Evidence for episodic sand-blow activity during

the 1811-1812 New Madrid (Missouri) earthquake series: Geology,

v. 17, no. 2, p. 103-106.

Sexton, J.L., 1988, Seismic reflection expression of reactivated structures in the New Madrid rift complex: Seismological Research

Letters, v. 59, no. 4, p. 141-150. 

Springer, F.M., Ullrich, C.R., and Hagerty, D.J., 1985, Streambank

stability: Proceedings of the American Society of Civil Engineers,

Journal of the Geotechnical Engineering Division, v. Ill, no. GT5,

p. 624-640. 

Taylor, K.B., 1991, Seismotectonics of the Illinois Basin and the

northern half of the Ozark Uplift: St. Louis, Mo., St. Louis

University, Ph.D. thesis, 150 p. 

Tuttle, M., Cowie, P., and Wolf, L., in press, Liquefaction induced by

modern earthquakes as a key to paleoseismicity—A case study of

the 1988 Saguenay earthquake: Proceedings of the 19th Water

Reactor Safety Information Meeting, U.S. Nuclear Regulatory

Commission, Washington, D.C. 

Wesnousky, S.G., and Leffler, L.M., in press, On the search for

paleoliquefaction in the New Madrid seismic zone: Seismological

Research Letters, v. 63, no. 3.

Youd, T.L., 1984, Recurrence of liquefaction at the same site: Proceedings of the Eighth World Conference on Earthquake Engineering, 

Earthquake Engineering Research Institute, San Francisco, 

Calif., v. 3, p. 231-238.

————1991, Mapping of earthquake-induced liquefaction for seismic 

zonation: Proceedings of the Fourth International Conference on 

Seismic Zonation, Earthquake Engineering Research Institute, El 

Cerrito, Calif., v. 1, p. 111-147.

Youd, T.L., and Hoose, S.N., 1978, Historic ground failures in 

northern California triggered by earthquakes: U.S. Geological 

Survey Professional Paper 993, 177 p.

Youd, T.L., and Perkins, D.M., 1978, Mapping liquefaction-induced 

ground failure potential: Proceedings of the American Society of 

Civil Engineers, Journal of the Geotechnical Engineering Division, 

v. 104, no. GT4, p. 433-446.

————1987, Mapping of Liquefaction Severity Index: Proceedings of 

the American Society of Civil Engineers, Journal of Geotechnical 

Engineering, v. 113, no. 11, p. 1374-1392.

Youd, T.L., Perkins, D.M., and Turner, W.G., 1989, Liquefaction 

Severity Index attenuation for the eastern United States, in 

O'Rourke, T.D., and Hamada, M., eds., Proceedings from the 

Second U.S.-Japan Workshop on Liquefaction, Large Ground 

Deformation, and Their Effects on Lifelines: State University of 

New York at Buffalo, Technical Report NCEER-S9-0032, p. 

438-452.

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