Prepared in cooperation with the U.S. Agency for International Development, 

Office of U.S. Foreign Disaster Assistance

Field Reconnaissance Report of Landslides Triggered by

the January 12, 2010, Haiti Earthquake

By Randall W. Jibson and Edwin L. Harp

Open-File Report 2011–1023

U.S. Department of the Interior

U.S. Geological Survey
ii

U.S. Department of the Interior

KEN SALAZAR, Secretary

U.S. Geological Survey

Marcia K. McNutt, Director

U.S. Geological Survey, Reston, Virginia: 2011 

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Suggested citation:

Jibson, R.W., and Harp, E.L., 2011, Field reconnaissance report of landslides triggered by the January 12, 2010, Haiti 

earthquake: U.S. Geological Survey Open-File Report 2011–1023, 19 p. 

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Although this report is in the public domain, permission must be secured from the individual 

copyright owners to reproduce any copyrighted material contained within this report.
iii

Contents

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

Activities ........................................................................................................................................................................ 2

Summary of Key Findings.............................................................................................................................................. 3

Landslide numbers and distribution ........................................................................................................................... 3

Landslide types.......................................................................................................................................................... 4

Landslide dams.......................................................................................................................................................... 5

Ongoing landslide hazards......................................................................................................................................... 5

Summary and Conclusion.............................................................................................................................................. 6

References Cited........................................................................................................................................................... 7

Figures

Figure 1. Preliminary map of locations of landslides triggered by the January 12, 2010, Haiti earthquake ............. 8

Figure 2. Dense concentration of landslides in limestone near the Enriquillo-Plantain Garden fault zone............... 9

Figure 3. Landslide cracks in weathered basalt 12.7 kilometers southwest of Carrefour....................................... 10

Figure 4. Earthquake-triggered landslide on southern coast of Haiti near village of Nan Diamant ........................ 11

Figure 5. Boulders of intact limestone that fell and rolled during the earthquake from cliffs along the EnriquilloPlantain Garden fault zone..................................................................................................................... 12

Figure 6. Rock fall that deposited disaggregated limestone fragments in river valley............................................ 13

Figure 7. Lateral-spread cracks along coast west of Port-au-Prince near Léogâne. ............................................. 14

Figure 8. Landslide dam 15 kilometers northwest of Jacmel.. ............................................................................... 15

Figure 9. Small lakes impounded by landslide dams along a 600-meter length of stream northwest of Jacmel.... 16
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Figure 10. Detached landslide blocks about 15 km northwest of Jacmel that could move further in future 

earthquakes or rain storms..................................................................................................................... 17

Figure 11. Extensional cracks behind the main scarp of the coastal landslide shown in figure 4. ........................... 18

Figure 12. Landslides that deposited sediment to a river valley along the Enriquillo-Plantain Garden fault zone 

about 6 kilometers south-southwest of Carrefour. .................................................................................. 19
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Conversion Factors

Multiply By To obtain

Length

centimeter (cm) 0.3937 inch (in.)

meter (m) 3.281 foot (ft) 

kilometer (km) 0.6214 mile (mi)

Volume

cubic meter (m3) 35.31 cubic foot (ft3)

cubic meter (m3) 1.308 cubic yard (yd3) 
1

Field Reconnaissance Report of Landslides Triggered

by the January 12, 2010, Haiti Earthquake

Prepared in cooperation with the U.S. Agency for International Development, 

Office of U.S. Foreign Disaster Assistance

By Randall W. Jibson and Edwin L. Harp

Introduction 

Shaking from the January 12, 2010, Haiti earthquake (M 7.0) caused devastating 

structural damage and triggered many landslides that blocked roads, dammed rivers and streams, 

and threatened infrastructure in many parts of Haiti. The earthquake had a complex mechanism 

that included both thrust and left-lateral strike-slip movement. We began analysis of satellite 

imagery to map triggered landslides almost immediately after the earthquake. When the scope of 

the disaster became clear, the U.S. Agency for International Development, Office of U.S. 

Foreign Disaster Assistance (OFDA), requested that the U.S. Geological Survey (USGS) assess 

various seismic hazards, including those from landslides. Using funding provided by OFDA, we 

departed for Haiti on March 25, 2010, to conduct a preliminary hazard assessment; the brief 

mission included aerial helicopter reconnaissance of areas affected by landslides and ground 

inspections at some accessible landslide sites. This brief report summarizes our activities and 

preliminary findings.
2

Activities

• January 13–March 24: Searched for usable satellite imagery from before and after the 

earthquake. Used imagery in Google Earth to compile a preliminary map of landslides 

triggered by the earthquake. Assembled available topographic maps. Consulted with other 

teams who had been to Haiti about logistics and field conditions. 

• March 25: Flew from Denver to Miami. Overnighted in Miami. 

• March 26: Flew from Miami to Port-au-Prince, Haiti. Moved into quarters at U.S. embassy 

provided by OFDA. Finalized arrangements for helicopter support and field guide (for 

driving and translation). 

• March 27–28: Conducted helicopter reconnaissance of areas affected by landslides. Landed 

at key areas to conduct field studies and assess hazards on the ground. Conducted ground 

reconnaissance of areas in the foothills above Port-au-Prince.

• March 29: Began compiling data and drafting preliminary report. Briefed OFDA staff at 

U.S. embassy in Haiti on initial findings of investigation.

• March 30: Flew from Port-au-Prince to Denver. 

• March 31–April 10: Completed initial trip report.

• April 10–September 30: Continued mapping of landslides from satellite imagery. 
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Summary of Key Findings

Landslide numbers and distribution

Imagery acquired soon after the earthquake by Google Earth has 60-centimeter (cm) 

resolution; using this imagery we produced a preliminary map of the point locations of landslides 

triggered in areas around the Enriquillo-Plantain Garden fault zone (fig. 1). More detailed 

mapping of landslides as polygons is partially completed and is continuing. Based on mapping 

completed to date, several observations can be made regarding the number and distribution of 

landslides triggered by the earthquake:

• We estimate that the earthquake triggered 4,000–5,000 landslides. This is within the range 

predicted by empirical studies of earthquake-triggered landslides worldwide that estimate 

numbers of landslides as a function of earthquake magnitude. (Keefer, 2002; Malamud and 

others, 2004). 

• The area affected by landslides extends about 60 kilometers (km) east and west from the 

earthquake epicenter and across the entire north-south extent of the peninsula west of Portau-Prince (fig. 1). Studies of earthquake-triggered landslides around the world indicate that 

the maximum distance limit for slides from a M 7.0 earthquake is about 200 km (Keefer, 

1984); thus, this earthquake appears to have produced shaking well below the maximum of 

similar historical earthquakes worldwide, as indicated by triggered landslides. 

• Landslide concentrations are greatest south of the Enriquillo-Plantain Garden fault zone, 

which could indicate either (1) stronger shaking in that area, or (2) higher landslide 

susceptibility of slopes in the area south of the fault zone. Our initial assessment suggests 

abundant susceptible slopes both north and south of the fault, which would argue in favor of 
4

lower shaking to the north. The extensive building damage north of the fault, however, 

suggests high-level shaking there. The lack of strong-motion seismic recordings in the area 

limits our ability to address fully the question of the asymmetrical landslide distribution.

• Landslide densities were greatest in deeply weathered, sheared, fractured, and (or) altered 

limestone (fig. 2). That material tends to disaggregate as downslope movement begins, and 

disrupted rock fragments form most of the landslide deposits. Weathered basalt slopes 

produced far fewer landslides; those slopes are less steep, more rounded, and, apparently, 

less susceptible to landsliding (fig. 3). 

Landslide types

Most of the landslides triggered by the earthquake were disrupted rock falls and rock 

slides in the limestone and weathered basalt that predominate in the region surrounding the 

Enriquillo-Plantain Garden fault (landslide terminology after Varnes, 1978). These landslides 

consist of partially or completely disrupted masses of rock that form on the steep slopes of 

deeply incised river valleys and coastal bluffs (fig. 4). Where the rock mass is harder and wellcemented, large blocks fell, slid, and (or) rolled down the slopes (fig. 5). In weaker rock, the 

material locally crumbled into smaller pieces and slid or flowed to the base of the slope (fig. 6). 

The predominance of disrupted rock falls and rock slides is consistent with observations from 

other earthquakes around the world (Keefer, 1984, 2002). Lateral spreads (horizontal movement 

of blocks of soil on nearly level ground) occurred at some port facilities in Port-au-Prince and 

along coastal areas to the west (fig. 7).
5

Landslide dams

Many of the landslides blocked stream drainages and impounded lakes. The larger 

landslide dams had already been breached, and streams were flowing through them in a stable 

state, at the time of our visit (fig. 8). Water downstream from these breached dams was running 

clear at the time of our investigation, which indicated that little or no upstream erosion was 

occurring. Some small lakes are still impounded in tributary valleys, and those likely will breach 

during future rainy seasons (fig. 9). Volumes of such lakes are not large enough to be of concern 

for downstream populations. During future rainy seasons, already-breached dams will be 

downcut slightly more but should not pose a significant hazard. The landslide dam blocking the 

Grand Goave River, 5 km south of Grand Goave, has breached and drained; no lake remains. 

Ongoing landslide hazards

Several ongoing potential landslide hazards exist. These hazards will be of particular 

concern during future earthquakes and rainy seasons:

• The earthquake shaking created many partially detached landslide masses. These are blocks 

of rock that moved but did not slide all the way to the bottom of the slope (fig. 10). Such 

blocks can be precarious, and renewed movement could occur in future earthquakes or during 

rainy periods. Renewed movement could damage areas downslope and could, in some 

places, form new landslide dams.

• Many landslides that initiated at the tops of slopes have related cracks behind the main scarp 

(fig. 11). These cracks indicate a potential for more landsliding—either during future 

earthquakes or rainy periods—which could enlarge the initial slide.
6

• Earthquake-triggered landslides have moved large amounts of loose sediment into stream 

drainages (fig. 12); additional material has been detached from slopes but has not slid all the 

way to the valley bottoms. During future rainy seasons this sediment associated with 

earthquake-triggered landslides will move into river systems and create significant increases 

in downstream sedimentation. The magnitude of this effect cannot be quantified with 

currently available data.

Summary and Conclusion

The January 12, 2010, Haiti earthquake (M 7.0) triggered 4,000–5,000 landslides 

consisting mainly of disrupted slides and falls in fractured, weathered, and (or) altered limestone

and basalt. The distribution of landslides suggests that the earthquake might have produced 

lower levels of shaking than would have been expected for a M 7.0 earthquake. It is thus 

possible that future earthquakes of equal or greater magnitude could trigger higher 

concentrations of landslides over a much broader region than did the January 2010 earthquake. 

The largest landslide dams have already breached; smaller landslide dams pose no serious 

threats. The most significant ongoing hazards include (1) partially detached landslide masses 

(some of which could form new landslide dams) that could remobilize in future earthquakes or 

rainy seasons; (2) cracks behind head scarps of landslides, which could indicate the potential for 

renewed and enlarged landslide movement; and (3) increased downstream sedimentation 

resulting from large quantities of sediment deposited in stream valleys by earthquake-triggered 

landslides. Continuing detailed mapping of landslides from satellite imagery should provide a 

clearer picture of landslide distribution and possible reasons for the relatively small area of 

landsliding and the asymmetrical landslide distribution. 
7

References Cited

Keefer, D.K., 1984, Landslides caused by earthquakes: Geological Society of America Bulletin, 

v. 95, p. 406–421. 

Keefer, D.K., 2002, Investigating landsliding caused by earthquakes—A historical review: 

Surveys in Geophysics, v. 23, p. 473–510. 

Malamud, B.D., Turcotte, D.L., Guzzetti, F., Reichenbach, P., 2004, Landslide inventories and 

their statistical properties: Earth Surface Processes and Landforms, v. 29, p. 687–711. 

Varnes, D.J., 1978, Slope movement types and processes, in Schuster, R.L., and Krizek, R.J., 

eds., Landslides—Analysis and Control: Transportation Research Board Special Report 176, 

Transportation Research Board, Washington, D.C., p. 11–33. 
8

Figure 1. Preliminary map of locations of landslides triggered by the January 12, 2010, Haiti earthquake 

as observed from imagery in Google Earth. Red crosses denote landslide locations; Enriquillo-Plantain 

Garden fault shown in green; small labeled red circles are towns and cities; blue squares are 

photograph locations in Google Earth. This map is not complete and shows only some of the triggered 

landslides; more thorough mapping is continuing. (Note the misspelling on this image of the town 

named Nan Diamant in the southwestern corner of the view.) Base image is copyrighted by Google, 

Inc., GeoEye, and DigitalGlobe, all 2010.
9

Figure 2. Dense concentration of landslides in limestone near the Enriquillo-Plantain Garden fault zone 

about 10 kilometers south-southwest of Carrefour.
10

Figure 3. Landslide cracks in weathered basalt 12.7 kilometers southwest of Carrefour. Note the soft, 

rounded topography of the basalt.
11

Figure 4. Earthquake-triggered landslide on southern coast of Haiti near village of Nan Diamant. 

Landslide is about 135 meters wide and has an estimated volume of 300,000 cubic meters.
12

Figure 5. Boulders of intact limestone that fell and rolled during the earthquake from cliffs along the 

Enriquillo-Plantain Garden fault zone.
13

Figure 6. Rock fall that deposited disaggregated limestone fragments in river valley. The landslide is 

about 200 meters wide and is 5.4 kilometers southwest of Carrefour.
14

Figure 7. Lateral-spread cracks along coast west of Port-au-Prince near Léogâne. 
15

Figure 8. Landslide dam 15 kilometers northwest of Jacmel. The dam has breached, and the small 

amount of water impounded upstream should pose no future hazard. The landslide is about 150 

meters wide.
16

Figure 9. Small lakes impounded by landslide dams along a 600-meter length of stream northwest of 

Jacmel. Yellow arrow shows general downstream direction.
17

Figure 10. Detached landslide blocks (arrows) about 15 km northwest of Jacmel that could move further in 

future earthquakes or rain storms.
18

Figure 11. Extensional cracks behind the main scarp of the coastal landslide shown in figure 4.
19

Figure 12. Landslides that deposited sediment to a river valley along the Enriquillo-Plantain Garden fault 

zone about 6 kilometers south-southwest of Carrefour.