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U.S. Department of the Interior
U.S. Geological Survey
Open-File Report 2021–1112
Earthquake Hazards Program and Landslide Hazards Program
Landslides Triggered by the August 14, 2021, Magnitude 7.2
Nippes, Haiti, Earthquake
Landslides Triggered by the August 14,
2021, Magnitude 7.2 Nippes, Haiti,
Earthquake
By Sabrina N. Martinez, Kate E. Allstadt, Stephen L. Slaughter, Robert Schmitt,
Elaine Collins, Lauren N. Schaefer, and Sonia Ellison
Earthquake Hazards Program and Landslide Hazards Program
Open-File Report 2021–1112
U.S. Department of the Interior
U.S. Geological Survey
U.S. Geological Survey, Reston, Virginia: 2021
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Suggested citation:
Martinez, S.N., Allstadt, K.E., Slaughter, S.L., Schmitt, R., Collins, E., Schaefer, L.N., and Ellison, S., 2021, Landslides
triggered by the August 14, 2021, magnitude 7.2 Nippes, Haiti, earthquake: U.S. Geological Survey Open-File Report
2021–1112, 17 p., https://doi.org/10.3133/ofr20211112 .
Associated data for this publication:
Martinez, S.N., Allstadt, K.E., Slaughter, S.L., Schmitt, R.G., Collins, E., Schaefer, L.N., and Ellison, S., 2021, Rapid
response landslide inventory for the 14 August 2021 M7.2 Nippes, Haiti, earthquake: U.S. Geological Survey data
release, https://doi.org/10.5066/P99MYPXK.
ISSN 2331-1258 (online)
iii
Acknowledgments
Funding for the preparation of this report was provided by the U.S. Agency for International
Development’s Bureau for Humanitarian Assistance and the U.S. Geological Survey. We thank
Robert Mason, Karl Winters, and Allen Gellis for their insights on channel sedimentation and
flooding and Jeff Coe, Randall Jibson, David Wald, and Ryan Gold for reviewing the report
(U.S. Geological Survey).
v
Contents
Acknowledgments����������������������������������������������������������������������������������������������������������������������������������������iii
Abstract�����������������������������������������������������������������������������������������������������������������������������������������������������������1
Introduction����������������������������������������������������������������������������������������������������������������������������������������������������1
Data and Analysis������������������������������������������������������������������������������������������������������������������������������������������3
Coseismic Landslides������������������������������������������������������������������������������������������������������������������������������������4
Ongoing Hazards������������������������������������������������������������������������������������������������������������������������������������������13
Landslide Dams�����������������������������������������������������������������������������������������������������������������������������������13
Landslide Hazards to Roads��������������������������������������������������������������������������������������������������������������13
Increased Landslide Activity������������������������������������������������������������������������������������������������������������13
Channel Sedimentation and Flooding����������������������������������������������������������������������������������������������14
Summary�������������������������������������������������������������������������������������������������������������������������������������������������������15
References Cited�����������������������������������������������������������������������������������������������������������������������������������������16
Figures
1. Overview of the Tiburon Peninsula showing contours of estimated peak ground
acceleration for the 2021 Nippes, Haiti, earthquake��������������������������������������������������������������2
2. Overview map of the Haiti 2021 earthquake landslide inventory showing
landslide dams, road hazards, and flagged landslides����������������������������������������������������������3
3. Flagged landslide features in Camp-Perrin commune, identified from satellite
imagery after the 2021 Haiti earthquake�����������������������������������������������������������������������������������8
4. Flagged landslide features in Pestel, Beaumont, Chantal, and Roseaux
communes, identified from satellite imagery after the 2021 Haiti earthquake�������������������9
5. Flagged landslide features in Maniche commune, identified from satellite
imagery after the 2021 Haiti earthquake���������������������������������������������������������������������������������10
6. Flagged landslide features in L’Asile commune, identified from satellite imagery
after the 2021 Haiti earthquake������������������������������������������������������������������������������������������������11
7. Flagged landslides in Cavaillon, Saint Louis du Sud, and Baradères communes,
identified from satellite imagery after the 2021 Haiti earthquake���������������������������������������12
8. Satellite imagery from Haiti after the 2021 earthquake and examples of two
landslide dams that were flagged as warranting continued monitoring��������������������������14
9. Map showing the relative density of landslides along 1,000-meter river
segments on the Tiburon Peninsula, Haiti, after the 2021 earthquake������������������������������15
Table
1. Notable landslide dams and road obstructions after the 2021 Nippes, Haiti,
earthquake�������������������������������������������������������������������������������������������������������������������������������������5
vi
Conversion Factors
International System of Units to U.S. customary units
Multiply By To obtain
Length
meter (m) 3.281 foot (ft)
kilometer (km) 0.6214 mile (mi)
kilometer (km) 0.5400 mile, nautical (nmi)
meter (m) 1.094 yard (yd)
Area
square kilometer (km
2
) 247.1 acre
square kilometer (km
2
) 0.3861 square mile (mi
2
)
Datum
Coordinate information is referenced to the World Geodetic System 1984 (WGS 84) Universal
Transverse Mercator (UTM) Zone 18N projection.
Abbreviations
DART disaster assistance response team
DEM digital elevation model
g acceleration of gravity
M magnitude
RMT response management team
UNICEF United Nations Children's Fund
USAID U.S. Agency for International Development
USGS U.S. Geological Survey
UTC coordinated universal time
UTM Universal Transverse Mercator
WGS World Geodetic System
Landslides Triggered by the August 14, 2021, Magnitude 7.2
Nippes, Haiti, Earthquake
By Sabrina N. Martinez,
1
Kate E. Allstadt,
1
Stephen L. Slaughter,
1,2
Robert Schmitt,
1
Elaine Collins,
1
Lauren N.
Schaefer,
1
and Sonia Ellison
1
1
U.S. Geological Survey
2
U.S. Agency for International Development, Bureau for Humanitarian
Assistance
Abstract
The August 14, 2021, magnitude 7.2 Nippes, Haiti,
earthquake triggered thousands of landslides on the Tiburon
Peninsula. The landslides directly caused fatalities and damage
and impeded response efforts by blocking roads and causing
other infrastructure damage. Adverse effects of the landslides
likely will continue for months to years. This report presents
an assessment of potential postearthquake landslide-related
geologic hazards for the Tiburon Peninsula and a preliminary
map of the landslides triggered by the earthquake. This hazard
assessment is based on an emergency analysis of the currently
available, postearthquake satellite imagery. In this report, we
highlight specific areas of concern that may benefit from more
detailed assessment and longer-term monitoring. Our mapping
efforts revealed that at least 4,893 landslides were triggered
across the Tiburon Peninsula by the earthquake and subse-
quent rainfall from Tropical Cyclone Grace. We also observed
hundreds of landslide deposits potentially restricting flow in
rivers and streams. In addition, we observed landslides that
likely affected roads by rendering them impassable or suscep-
tible to subsequent damage from existing landslides. Because
of the preliminary nature of this report and the limits of remote
analyses, additional investigation and monitoring would be
beneficial to accurately determine the threat posed by these
hazards to people and infrastructure.
Introduction
The magnitude (M) 7.2 Nippes, Haiti, earthquake
occurred at 12:29:08 coordinated universal time (08:29:08
local time) on August 14, 2021. The rupture started in the
center of the Tiburon Peninsula, about 125 kilometers (km)
west of the capital, Port-au-Prince, and ruptured primarily
westward with reverse and left-lateral strike-slip motion along
the Enriquillo-Plantain Garden fault zone. The fault rup-
ture terminated in the vicinity of Pic Macaya National Park.
Shaking was estimated by the U.S. Geologial Survey (USGS)
ShakeMap (ver. 14) to have exceeded 0.5 g (acceleration of
gravity) along an 80-km band of steep and rugged, and there-
fore landslide-susceptible, terrain in the center of the Tiburon
Peninsula (fig. 1). The USGS near-real-time ground failure
product (Allstadt and others, 2021) estimated that the land-
slides triggered by the Nippes earthquake would be significant
in number and (or) spatial extent (estimated at about 70 square
kilometers) and that the number of people living near landslide
hazards was significant (estimated at about 9,000 people).
The landslide probability map produced by the ground failure
product is shown in figure 1. The earthquake was followed by
Tropical Cyclone Grace, which was estimated to have dropped
5–10 inches of rain in Haiti on August 16, 2021 ( National
Oceanic and Atmospheric Administration, 2021), and likely
triggered additional landslides. More information about the
earthquake, including the near-real-time products, is available
from the USGS earthquake event page at https:// earthquake
.usgs.gov/earthquakes/ eventpage/ us6000f65h/executive .
During the week following the earthquake, a team of
USGS scientists rapidly mapped landslides using remote
methods and created a landslide inventory. By the end of
this effort, 3,625 landslides had been mapped. This inven-
tory, with critical daily observations, was shared with the
U.S. Agency for International Development’s (USAID’s)
Disaster Assistance Response Team (DART) and Response
Management Team (RMT) for situational awareness and
emergency response. The inventory also was made publicly
available as an ArcGIS online web map for use by humanitar-
ian aid organizations for situational awareness and emergency
response. The original rapid inventory that was available
immediately after the earthquake for situational awareness
only is now superseded by the inventory associated with this
report (Martinez and others, 2021).
For this report, we mapped additional landslides that
were missed in the initial inventory. We carefully reviewed the
inventory in its entirety to identify landslides that may pose
ongoing threats to people and property (fig. 2). We mapped,
as best as possible, the location of each landslide’s heads-
carp area as a point feature. Some mapped locations may be
2 Landslides Triggered by the August 14, 2021, Magnitude 7.2 Nippes, Haiti, Earthquake
imprecise because of the poor orthorectification of some of the
satellite imagery used. Landslide polygons were not mapped
for this preliminary version of the inventory. Most imagery
available for the affected area was obtained after the passage
of Tropical Cyclone Grace; thus, the landslide inventory pre-
sented could contain both earthquake- and rainfall-triggered
landslides. However, we did not see many landslides with
characteristics common to rainfall-triggered landslides, such
as channelized flows, so we think that most of the landslides
were triggered by the earthquake.
In addition to landslide headscarp locations, we present
an assessment of potential postearthquake landslide-related
geologic hazards for the Tiburon Peninsula. We highlight
specific areas of concern that may benefit from more detailed
assessment and longer-term monitoring because of the poten-
tial effects on people and infrastructure. Potential postearth-
quake landslide hazards include (1) sudden flooding from the
failure of landslide dams; (2) continued landsliding of dam-
aged slopes, especially along roads and river channels; (3) an
overall increase in landslide activity for multiple years; and
(4) changes in river behavior from an influx of landslide sedi-
ment that can lead to long-term changes in flooding risks. USGS GF model landslide probability EXPLANATION