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U.S. Geological Survey response to Hurricane Maria flooding in Puerto Rico and characterization of peak streamflows observed September 20–22, 2017

Hurricane Maria struck the island of Puerto Rico on September 20, 2017, as a Category 4 storm. The hurricane traversed the island from southeast to northwest and produced recorded 48-hour rainfall totals of up to 30.01 inches. Estimates of the human death toll range from 2,975 to 4,645, possibly more.The U.S. Geological Survey (USGS) hydrologic monitoring network sustained substantial wind and flo

Rigorously valuing the impact of Hurricanes Irma and Maria on coastal hazard risks in Florida and Puerto Rico

The degradation of coastal habitats, particularly coral reefs, raises risks by increasing the exposure of coastal communities to flooding hazards. In the United States, the physical protective services provided by coral reefs were recently assessed in social and economic terms, with the annual protection provided by U.S. coral reefs off the coasts of the State of Florida and the Commonwealth of Pu

Land-based sediment sources and transport to southwest Puerto Rico coral reefs after Hurricane Maria, May 2017 to June 2018

The effects of runoff from land on nearshore ecosystems, including coral reef communities, are influenced by both sediment supply and removal by coastal processes. Integrated studies across the land-sea interface describing sources and transport of terrestrial sediment and its nearshore fate allow reef protection initiatives to target key onshore and offshore areas. Geochemical signatures in the f

Rapid observations of ocean dynamics and stratification along a steep island coast during Hurricane María

Hurricanes are extreme storms that affect coastal communities, but the linkages between hurricane forcing and ocean dynamics remain poorly understood. Here, we present full water column observations at unprecedented resolution from the southwest Puerto Rico insular shelf and slope during Hurricane María, representing a rare set of high-frequency, subsurface, oceanographic observations collected al

Debris-flow growth in Puerto Rico during Hurricane Maria: Preliminary results from analyses of pre- and post-event lidar data

On September 20, 2017, Hurricane Maria triggered widespread debris flows in Puerto Rico. We used field observations and pre- and post-Maria lidar to study the volumetric growth of long-travelled (>400 m) debris flows in four basins. We found overall growth rates that ranged from 0.7 to 30.4 m3 per meter of channel length. We partitioned the rates into two growth mechanisms, aggregation of multiple

Mobility characteristics of landslides triggered by Hurricane Maria in Puerto Rico

Mobility is an important element of landslide hazard and risk assessments yet has been seldom studied for shallow landslides and debris flows in tropical environments. In September 2017, Hurricane Maria triggered > 70,000 landslides across Puerto Rico. Using aerial imagery and a lidar digital elevation model (DEM), we mapped and characterized the mobility of debris slides and flows in four differe

Controls on sediment transport over coral reefs off southwest Puerto Rico: Seasonal patterns and Hurricane Maria

Guánica Bay in southwest Puerto Rico is highly turbid and has some of the highest PCB concentrations in the USA. To investigate how and to what extent the bay waters influence coral reef ecosystem health along the coastline, 6 months of hydrodynamic data were collected at 8 sites on the insular shelf. Bed shear stresses were primarily driven by waves and were weakest at the site closest to La Parg

Landslides triggered by Hurricane Maria: Assessment of an extreme event in Puerto Rico

Hurricane Maria hit the island of Puerto Rico on 20 September 2017 and triggered more than 40,000 landslides in at least three-fourths of Puerto Rico’s 78 municipalities. The number of landslides that occurred during this event was two orders of magnitude greater than those reported from previous hurricanes. Landslide source areas were commonly limited to surficial soils but also extended into und

2018 hurricane and wildfire supplemental funding: USGS recovery activities

The Additional Supplemental Appropriations for Disaster Relief Requirements Act, 2018 (P.L. 115-123), was signed by the President on February 9, 2018. This funding provided $42.2 million to the U.S. Geological Survey (USGS) for equipment repair and replacement, high-resolution elevation data collection in both hurricane- and wildfire-impacted areas, and scientific studies and assessments that will

Seismic sensors record a hurricane’s roar

The instruments installed at Global Seismographic Network (GSN) stations were designed to record Earth’s vibrations, but they sometimes pick up sound waves from unexpected sources. For example, newly installed infrasound sensors at a station on Puerto Rico recorded the passage of Hurricane Maria on 20 September 2017.

Preliminary peak stage and streamflow data at selected streamgaging stations in North Carolina and South Carolina for flooding following Hurricane Matthew, October 2016

The passage of Hurricane Matthew across the central and eastern regions of North Carolina and South Carolina during October 7–9, 2016, resulted in heavy rainfall that caused major flooding in parts of the eastern Piedmont in North Carolina and coastal regions of both States. Rainfall totals of 3 to 8 inches and 8 to more than 15 inches were widespread throughout the central and eastern regions, re

Identifying and preserving high-water mark data

High-water marks provide valuable data for understanding recent and historical flood events. The proper collection and recording of high-water mark data from perishable and preserved evidence informs flood assessments, research, and water resource management. Given the high cost of flooding in developed areas, experienced hydrographers, using the best available techniques, can contribute high-qual