Unified Interior Regions
Guam
The Pacific Region has nine USGS Science Centers in California, Nevada, and Hawaii. The Regional Office, headquartered in Sacramento, provides Center oversight and support, facilitates internal and external collaborations, and works to further USGS strategic science directions.
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The Pacific Region has nine USGS Science Centers in California, Nevada, and Hawaii. The Regional Office, headquartered in Sacramento, provides Center oversight and support, facilitates internal and external collaborations, and works to further USGS strategic science directions.
News
Invasive Brown Treesnake Present on Cocos Island, Agencies Working to Prevent Further Spread
For the first time, an invasive brown treesnake population has been found on Cocos Island, an 83.1 acre atoll located 1.5 miles off the southwest coast of Guam.
Assessment of Mercury Bioaccumulation in US National Parks Using Citizen Science
A team of federal, academic, and NGO researchers conducted a national-scale assessment of mercury bioaccumulation in aquatic ecosystems using dragonfly larvae as biosentinels.
USGS Brown Treesnake Research Continues at Guam National Wildlife Refuge
On May 14, Director Reilly signed a Memorandum of Agreement with the Department of the Navy and the U.S. Fish and Wildlife Service. The MOA provides for continuity of operations for the USFWS and the USGS with construction of new office and lab facilities on the Guam National Wildlife Refuge in conjunction with DOD’s construction of a Marine Corps firing range.
Publications
Rigorously valuing the role of U.S. coral reefs in coastal hazard risk reduction
The degradation of coastal habitats, particularly coral reefs, raises risks by increasing the exposure of coastal communities to flooding hazards. The protective services of these natural defenses are not assessed in the same rigorous economic terms as artificial defenses, such as seawalls, and therefore often are not considered in decision making...
Storlazzi, Curt D.; Reguero, Borja G.; Cole, Aaron D.; Lowe, Erik; Shope, James B.; Gibbs, Ann E.; Nickel, Barry A.; McCall, Robert T.; van Dongeren, Ap R.; Beck, Michael W.
Tropical cyclone projections: Changing climate threats for Pacific Island defense installations
Potential changing climate threats in the tropical and subtropical North Pacific Ocean were assessed, using coupled ocean-atmosphere and atmosphere-only general circulation models, to explore their response to projected increasing greenhouse gas emissions. Tropical cyclone occurrence, described by their frequency and intensity, near islands...
Widlansky, Matthew J.; Annamalai, Hariharasubramanian; Gingerich, Stephen B.; Storlazzi, Curt D.; Marra, John J.; Hodges, Kevin I.; Choy, Barry; Kitoh, Akio Climate trends and projections for Guam
The island of Guam experiences a tropical marine climate, which is warm and humid moderated by seasonal tradewinds and a wet and dry season. The dry season lasts from January to June, while the rainy months are from July to December. Annual rainfall totals 84-116 inches (2133-2946 mm), of which two-thirds fall during the rainy season. Seasonal...
Gingerich, Stephen B.; Keener, Victoria; Finucane, Melissa L.
Low-lying areas of tropical Pacific islands
Sea level is rising faster than projected in the western Pacific, so understanding how wave-driven coastal flooding will affect inhabited, low-lying islands—most notably, the familiar ring-shaped atolls—as well as the low-elevation areas of high islands in the Pacific Ocean, is critical for decision-makers in protecting infrastructure or relocating resources and people.
Coral Reef Project
Explore the fascinating undersea world of coral reefs. Learn how we map, monitor, and model coral reefs so we can better understand, protect, and preserve our Nation's reefs.
Sea-Level Rise and Climate Change Impacts to Reefs
Learn how the USGS studies sea-level rise and climate change impacts to coral reefs.
The Value of U.S. Coral Reefs for Risk Reduction
Summary of the report, “Rigorously valuing the role of U.S. coral reefs in coastal hazard risk reduction”
Circulation and Sediment, Nutrient, Contaminant, and Larval Dynamics on Reefs
The overall objective of this research effort is to better understand how circulation and sediment processes impact coral reefs.
Coral Reef Project: Guam
As part of the USGS Coral Reef Project, the USGS is working on the west coast of Guam to help determine the effects of sedimentation in nearshore waters.
United States Assessments of Undiscovered Oil and Gas Resources
USGS Energy Resources Program provides periodic assessments of the oil and natural gas endowment of the United States and the World. This website provides access to new, prioritized, assessment results and supporting data for the United States, as part of the Energy Policy and Conservation Act (EPCA).
Risk Analysis of Invasive Freshwater Fishes in Hawaii and Micronesia
Invasive species threaten biodiversity around the world, especially on islands. USGS scientists are helping to identify fish species that have the greatest potential to invade the fresh waters of Microneisa.
Exploring: Reservoir Capacity And Sedimentation Of The Fena Valley Reservoir Guam
The Fena Valley Reservoir, located in southern Guam, is the primary source of water for the United States Naval Base Guam and nearby village residents. At full capacity, the reservoir surface area extends approximately 0.30 mi2, and drains a watershed area of about 5.88 mi2. After reservoir construction, periodic bathymetric surveys, coupled with sedimentation models, ...
Coral Reef Facts
These facts about coral reefs are presented in conjunction with the USGS Coral Reef Project.
Guam (GUA)
The Guam observatory was established in 1957. The observatory is situated on property owned by the U.S. Air Force according to terms of an agreement with the USGS and the Geomagnetism Program. The facility is shared with the USGS Fort Collins Science Center (FORT) ...
Coastal and Marine Geoscience Data System
Information about scientific data collected through field activities conducted by scientists in the USGS Coastal and Marine Hazards and Resources program
National Water Information System (NWIS) Mapper
The NWIS mapper provides access to over 1.5 million sites contained in the USGS National Water Information System (NWIS), including sites where current and historical surface-water, groundwater, springs, and atmospheric data has been collected. Users can search by site type, data type, site number, or place.
Projected flood extent polygons and flood depth points based on 10-, 50-, 100-, and 500-year wave-energy return periods, with and without coral reefs, for the State of Hawaii (the islands of Hawaii, Kahoolawe, Kauai, Lanai, Maui, Molokai, Niihau, and Oahu
This part of the data release presents projected flooding extent polygon (flood masks) and flooding depth points (flood points) shapefiles based on wave-driven total water levels for the State of Hawaii (the islands of Hawaii, Kahoolawe, Kauai, Lanai, Maui, Molokai, Niihau, and Oahu). For each island there are 8 associated flood mask and flood depth shapefiles: one for
Projected flood extent polygons and flood depth points based on 10-, 50-, 100-, and 500-year wave-energy return periods, with and without coral reefs, for the Territory of Puerto Rico (the islands of Culebra, Puerto Rico, and Vieques)
This part of the data release presents projected flooding extent polygon (flood masks) and flooding depth points (flood points) shapefiles based on wave-driven total water levels for the Territory of Puerto Rico (the islands of Culebra, Puerto Rico, and Vieques). For each island there are 8 associated flood mask and flood depth shapefiles: one for each four nearshore wave energy
Projected flood extent polygons and flood depth points based on 10-, 50-, 100-, and 500-year wave-energy return periods, with and without coral reefs, for the Territory of Guam
This part of the data release presents projected flooding extent polygon (flood masks) and flooding depth points (flood points) shapefiles based on wave-driven total water levels for the Territory of Guam. There are 8 associated flood mask and flood depth shapefiles: one for each of four nearshore wave energy return periods (rp; 10-, 50-, 100-, and 500-years) and both with %
Projected flooding extents and depths based on 10-, 50-, 100-, and 500-year wave-energy return periods, with and without coral reefs, for the States of Hawaii and Florida, the Territories of Guam, American Samoa, Puerto Rico, and the U.S. Virgin Islands,
This data release provides flooding extent polygons (flood masks) and depth values (flood points) based on wave-driven total water levels for 22 locations within the States of Hawaii and Florida, the Territories of Guam, American Samoa, Puerto Rico, and the U.S. Virgin Islands, and the Commonwealth of the Northern Mariana Islands. For each of the 22 locations there are eight ass
Habitat characterization around standard brown treesnake traps on Guam, 2004 - 2017
Data were collected in association with locations of standard brown treesnake traps on Guam at location prior to suppression or control efforts and after control had occurred. In all cases study sites were closed or semi-closed populations of brown treesnakes. Habitat data focused on type and structure of the habitat within 10-m of the trap.
Dataset: Forest growth in and around an ungulate enclosure on Northern Guam, 2005-2011
On an island largely devoid of native vertebrate seed dispersers, we monitored forest succession for seven years following ungulate exclusion from a 5-hectare area and adjacent plots with ungulates still present.
National Water Information System web interface (NWISweb)
The National Water Information System (NWIS) web application provides access to real-time and historical surface-water, groundwater, water-quality, and water-use data collected at approximately 1.5 million sites across all 50 states.
Dataset: Forest growth in and around an ungulate enclosure on Northern Guam, 2005-2011
On an island largely devoid of native vertebrate seed dispersers, we monitored forest succession for seven years following ungulate exclusion from a 5-hectare area and adjacent plots with ungulates still present. The study site was in northern Guam on Andersen Air Force Base (13°37’N, 144°51’E) and situated on a coralline limestone plateau. We established 22 plot
Southern Guam watershed model, PRMS_2016
The PRMS_2016 folder contains the input files needed to run each of the modeled regions in southern Guam, the calibration data files, and a README_PRMS_2016.txt document that describes the contents of this archive and the execution of the model batch files.
Hydrologic Response Units (HRUs) for the Southern Guam watershed model, PRMS_2016
The hydrologic response units (HRUs) available here were used in the Precipitation Runoff Modeling System (PRMS) of southern Guam documented by Rosa and Hay (2017). A Geographic Information System (GIS) file for the HRUs is provided as a shapefile with attributes ParentHRU, Region, and RegionHRU identifying the numbering convention used in the PRMS_2016 southern Guam model par
This map shows the provinces assessed by the USGS for undiscovered oil and gas resources.
The 3DEP products and services available through The National Map consist of standard digital elevation models (DEMs) at various horizontal resolutions, elevation source and associated datasets, an elevation point query service and bulk point query service. All 3DEP products are available, free of charge and without use restrictions.
Rigorously valuing the role of U.S. coral reefs in coastal hazard risk reduction
The degradation of coastal habitats, particularly coral reefs, raises risks by increasing the exposure of coastal communities to flooding hazards. The protective services of these natural defenses are not assessed in the same rigorous economic terms as artificial defenses, such as seawalls, and therefore often are not considered in decision making...
Storlazzi, Curt D.; Reguero, Borja G.; Cole, Aaron D.; Lowe, Erik; Shope, James B.; Gibbs, Ann E.; Nickel, Barry A.; McCall, Robert T.; van Dongeren, Ap R.; Beck, Michael W. Tropical cyclone projections: Changing climate threats for Pacific Island defense installations
Potential changing climate threats in the tropical and subtropical North Pacific Ocean were assessed, using coupled ocean-atmosphere and atmosphere-only general circulation models, to explore their response to projected increasing greenhouse gas emissions. Tropical cyclone occurrence, described by their frequency and intensity, near islands...
Widlansky, Matthew J.; Annamalai, Hariharasubramanian; Gingerich, Stephen B.; Storlazzi, Curt D.; Marra, John J.; Hodges, Kevin I.; Choy, Barry; Kitoh, Akio
Storage capacity of the Fena Valley Reservoir, Guam, Mariana Islands, 2014
The Fena Valley Reservoir is in southern Guam and is the primary source of water for the U.S. Naval Base Guam and nearby village residents. Since the construction of the Fena Dam in 1951, sediment has accumulated in the reservoir and reduced its storage capacity. The reservoir was surveyed previously in 1973, 1979, and 1990 to estimate the loss in...
Marineau, Mathieu D.; Wright, Scott A. Climate trends and projections for Guam
The island of Guam experiences a tropical marine climate, which is warm and humid moderated by seasonal tradewinds and a wet and dry season. The dry season lasts from January to June, while the rainy months are from July to December. Annual rainfall totals 84-116 inches (2133-2946 mm), of which two-thirds fall during the rainy season. Seasonal...
Gingerich, Stephen B.; Keener, Victoria; Finucane, Melissa L.
The effects of withdrawals and drought on groundwater availability in the Northern Guam Lens Aquifer, Guam
Owing to population growth, freshwater demand on Guam has increased in the past and will likely increase in the future. During the early 1970s to 2010, groundwater withdrawals from the limestone Northern Guam Lens Aquifer, the main source of freshwater on the island, tripled from about 15 to 45 million gallons per day. Because of proposed military...
Gingerich, Stephen B. Estimating hydraulic properties from tidal attenuation in the Northern Guam Lens Aquifer, territory of Guam, USA
Tidal-signal attenuations are analyzed to compute hydraulic diffusivities and estimate regional hydraulic conductivities of the Northern Guam Lens Aquifer, Territory of Guam (Pacific Ocean), USA. The results indicate a significant tidal-damping effect at the coastal boundary. Hydraulic diffusivities computed using a simple analytical solution for...
Rotzoll, Kolja; Gingerich, Stephen B.; Jenson, John W.; El-Kadi, Aly I. Freshwater and drought on Pacific Islands
Izuka, Scot K.; Keener, Victoria
Seismic hazard assessment for Guam and the Northern Mariana Islands
We present the results of a new probabilistic seismic hazard assessment for Guam and the Northern Mariana Islands. The Mariana island arc has formed in response to northwestward subduction of the Pacific plate beneath the Philippine Sea plate, and this process controls seismic activity in the region. Historical seismicity, the Mariana megathrust,...
Mueller, Charles S.; Haller, Kathleen M.; Luco, Nicholas; Petersen, Mark D.; Frankel, Arthur D.
A water-budget model and estimates of groundwater recharge for Guam
On Guam, demand for groundwater tripled from the early 1970s to 2010. The demand for groundwater is anticipated to further increase in the near future because of population growth and a proposed military relocation to Guam. Uncertainty regarding the availability of groundwater resources to support the increased demand has prompted an investigation...
Johnson, Adam G.
Groundwater availability study for Guam; goals, approach, products, and schedule of activities
An expected significant population increase on Guam has raised concern about the sustainability of groundwater resources. In response, the U.S. Geological Survey (USGS), in collaboration with the University of Guam's Water and Environmental Research Institute of the Western Pacific (WERI) and with funding from the U.S. Marine Corps (USMC), is...
Gingerich, Stephen B.; Jenson, John W.
Ground Water on Tropical Pacific Islands - Understanding a Vital Resource
To a casual observer, tropical Pacific islands seem idyllic. Closer scrutiny reveals that their generally small size makes them particularly vulnerable to economic and environmental stresses imposed by rapidly growing populations, increasing economic development, and global climate change. On these islands, freshwater is one of the most precious...
Tribble, Gordon Rainfall-Runoff and Water-Balance Models for Management of the Fena Valley Reservoir, Guam
The U.S. Geological Survey's Precipitation-Runoff Modeling System (PRMS) and a generalized water-balance model were calibrated and verified for use in estimating future availability of water in the Fena Valley Reservoir in response to various combinations of water withdrawal rates and rainfall conditions. Application of PRMS provides a physically...
Yeung, Chiu W.
Scientist holding brown treesnake
A USGS scientist holds an invasive brown treesnake.
How Our Reefs Protect Us: Valuing the Benefits of U.S. Reefs
The degradation of coastal habitats, particularly coral reefs, raises risks by increasing the exposure of coastal communities to flooding hazards during storms. The protective services of these natural defenses are not assessed in the same rigorous economic terms as artificial defenses, such as seawalls, and therefore often are not considered in decision-making. Here we
Guam and CNMI Coral Reefs and Coastal Hazard Risk Reduction
Rigorously Valuing the Role of Guam’s Coral Reefs and the Commonwealth of the Northern Mariana Islands’s Coral Reefs in Coastal Hazard Risk Reduction
Estimated Annual Benefits
Maps of Guam and the the Commonwealth of the Northern Mariana Islands showing the distribution of the value of averted direct building damages, indirect economic activity losses, and
...
How Our Reefs Protect Us: Valuing the Benefits of U.S. Reefs (AD)
The degradation of coastal habitats, particularly coral reefs, raises risks by increasing the exposure of coastal communities to flooding hazards during storms. The protective services of these natural defenses are not assessed in the same rigorous economic terms as artificial defenses, such as seawalls, and therefore often are not considered in decision-making. Here we
Guam satellite image
Satellite photo of Guam from NASA’s Earth Observing-1 (EO-1) satellite's Advanced Land Imager.
A brown treesnake on frangipangi blossoms
A brown treesnake crawls on some frangipangi blossoms in Guam.
A brown treesnake in a tree in Guam.
This is an image of a brown treesnake in a tree in Guam, taken in 2009.
A brown treesnake in a tree in Guam.
A brown treesnake in a tree in Guam. Photo by Bob Reed, USGS, 2009.
Fish and coral in Tumon Bay Marine Reserve, Guam
Underwater photograph of Tumon Bay Marine Reserve, Guam, showing some of the amazing biologic diversity of coral reefs.
Guam Geomagnetic Observatory
Variations building at Guam geomagnetic observatory.
Aggregates Data by State, Type, and End Use; 1971–2016
This data set contains supplemental aggregates data for the USGS Minerals Yearbook Volume II—Area Reports: Domestic. It contains data for the years 1971 through 2016 and replaces the discrete construction aggregate tables that were included in the individual State chapters prior to 2014. It contains
For the first time, an invasive brown treesnake population has been found on Cocos Island, an 83.1 acre atoll located 1.5 miles off the southwest coast of Guam.
A team of federal, academic, and NGO researchers conducted a national-scale assessment of mercury bioaccumulation in aquatic ecosystems using dragonfly larvae as biosentinels.
On May 14, Director Reilly signed a Memorandum of Agreement with the Department of the Navy and the U.S. Fish and Wildlife Service. The MOA provides for continuity of operations for the USFWS and the USGS with construction of new office and lab facilities on the Guam National Wildlife Refuge in conjunction with DOD’s construction of a Marine Corps firing range.
Budget Focuses on Bringing Science, Facilities, and Infrastructure into the 21st Century
Research by the USGS and Dickinson College reveals why scientists fail to detect brown treesnakes at low densities
Guam’s water demands are anticipated to increase. Potential impacts of sea-level rise and a changing climate on surface-water and groundwater resources are assessed.
First-of-its-kind survey shows that algal toxins are found nationwide
Two recent reports of two brown treesnakes on Saipan is prompting federal and state officials to urge citizens of Hawaii, Guam and other Pacific Islands to report any sightings of these invasive snakes to authorities. Snakes can be reported by calling (671) 777-HISS or (670) 28-SNAKE.
A newly published, three-volume “Remote Sensing Handbook” is a comprehensive coverage of all remote sensing topics written by over 300 leading global experts.
SANTA CRUZ, Calif. — A new study shows that the combined effect of storm-induced wave-driven flooding and sea level rise on island atolls may be more severe and happen sooner than previous estimates of inundation predicted by passive “bathtub” modeling for low-lying atoll islands, and especially at higher sea levels forecasted for the future due to climate change.
Islands used by tropical seabirds are highly vulnerable to sea level rise according to a new study released today.
SANTA CRUZ, Calif. — The projected upsurge of severe El Niño and La Niña events will cause an increase in storm events leading to extreme coastal flooding and erosion in populated regions across the Pacific Ocean, according to a multi-agency study published today in Nature Geoscience.
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Locations
Pacific Islands Water Science Center
Phone: 808-690-9600
Fax: 808-690-9599
Pacific Island Ecosystems Research Center
Phone: (808) 985-6420
Fax: (808) 967-8568
Pacific Islands Climate Adaptation Science Center
USGS Brown Treesnake Laboratory and Rapid Response Facility
Phone: 671-637-7834