In Next Decades, Frequency of Coastal Flooding Will Double Globally
May 8—The frequency and severity of coastal flooding throughout the world will increase rapidly and eventually double in frequency over the coming decades even with only moderate amounts of sea-level rise, according to a new study released in Scientific Reports. This increase in flooding will be greatest and most damaging in tropical regions, impairing the economies of coastal cities and the habitability of low-lying Pacific island nations. Many of the world's largest populated low-lying deltas (such as the Ganges, Indus, Yangtze, Mekong and Irrawaddy Rivers), also fall in or near this affected tropical region. The report shows that with just 10 to 20 centimeters (4 to 8 inches) of sea-level rise expected no later than 2050, coastal flooding will more than double. This dramatic increase in coastal flooding results from rising sea levels combined with storm-driven flooding, including the effects of waves and storm surge. In most coastal regions, the amount of sea-level rise occurring over years to decades is small, yet even gradual sea-level rise can rapidly increase the frequency and severity of coastal flooding.
Ocean Absorption of Carbon Dioxide More than Makes Up for Methane Emissions from Seafloor Methane Seeps
May 8—The ocean waters near the surface of the Arctic Ocean absorbed 2,000 times more carbon dioxide from the atmosphere than the amount of methane that escaped into the atmosphere from the same waters, according to a study by the USGS Gas Hydrates Project and collaborators in Germany and Norway. The study was conducted near Norway’s Svalbard Islands, above several seafloor methane seeps. Methane is a more potent greenhouse gas than carbon dioxide, but the removal of carbon dioxide from the atmosphere where the study was conducted more than offset the potential warming effect of the methane emissions that were observed. “If what we observed near Svalbard occurs more broadly at similar locations around the world, it could mean that methane seeps have a net cooling effect on climate, not a warming effect, as we previously thought,” said USGS biogeochemist John Pohlman, the paper’s lead author.
Underwater Secrets of the Hayward Fault Zone: Integrated 3D imaging to understand earthquake hazards
May 2—USGS Research Geophysicist Janet Watt presented a public lecture titled “Underwater Secrets of the Hayward Fault Zone” on Thursday, May 25, at 7 pm in the USGS Rambo Auditorium in Building 3, 345 Middlefield Road, Menlo Park, California. Watt discussed how underwater imaging provides a unique opportunity to study urban fault hazards. These techniques can help answer questions such as: How do we link surface structures to depths where earthquakes occur? How does “acoustic trenching” help us understand earthquake history? The lecture was also broadcast live online.
Wildlife Recovery Following the Exxon Valdez Oil Spill was Highly Variable Across Species
May 2—Thanks to a quarter-century of research and monitoring, scientists now know how different wildlife species were injured by the 1989 Exxon Valdez oil spill and how long it took for populations to recover. This information may have important implications when responding to other oil spills, when conducting damage-assessment studies after spills and when considering the environmental risks associated with extracting and shipping oil. “Because wildlife species in the spill area vary so much in terms of what they eat, habitats that they use, and their ability to rebound after a decline in numbers, researchers saw huge differences in how long it took for populations to recover,” said Dan Esler, a research wildlife biologist with the USGS and lead author of a recently released paper on the subject. “Some species were barely affected, others such as bald eagles, rebounded quickly, and other species took much longer to recover, such as sea otters.”
Geologic Map Released for Mauna Loa's Northeast Flank
May 1—USGS authors Frank Trusdell and John Lockwood published Geologic map of the northeast flank of Mauna Loa volcano, Island of Hawai‘i, Hawaii, USGS Scientific Investigations Map 2932-A. This map refines knowledge of hazards and risks from Earth's largest active volcano. It encompasses the northeast flank of Mauna Loa from the 10,880-foot (3,316-meter) elevation to sea level, including the towns of Hilo and Volcano. The map shows the distribution of 105 lava flows from more than 30,000 years B.P. to A.D.
Asian Carp Would Have Adequate Food to Survive in Lake Michigan
April 26—If invasive bighead carp and silver carp spread into Lake Michigan, there would be enough food available for these species of Asian carp to survive, according to a new study by the USGS. This information is critical in helping resource managers mitigate effects of an Asian carp invasion. Great Lakes fisheries generate economic activity of approximately $7 billion annually in the United States alone. Due to the introduction or invasion of many non-native species, Lake Michigan’s ecosystem has already undergone broad and rapid change in fish and other aquatic life. If bighead and silver carp were to populate Lake Michigan, they have the potential to adversely affect the ecosystem and fishing industry.
Mapping the World’s Ocean Ecosystems
April 24—Baseline data needed to help scientists detect changes and to help nations protect living marine resources from depletion are now better understood thanks to state-of-the-art mapping technologies. To meet the need for a consistent, objective, and complete description of open-ocean environments, the Group on Earth Observations charged USGS ecologist Roger Sayre with a task to map the world’s ocean ecosystems. In response, the USGS formed a public-private partnership with ESRI, NOAA, academia, and non-profit organizations to produce the first ever detailed maps that group the entire global ocean into 37 distinct 3-D ecosystems. The groundbreaking work to produce the first-of-its-kind, objective, and true 3-D global marine-ecosystems maps is described in two recent USGS-led publications in the journal Oceanography and an AAG Special Publication. The resulting ecosystem data and maps are available in a web-based app called the Ecological Marine Unit Explorer.
Proven Under Pressure: USGS Advances Capabilities for High-Pressure Seafloor Samples Containing Gas Hydrate
April 14—In 2015, a drilling expedition staffed by scientists from India, Japan, and the United States discovered widespread, high-saturation accumulations of natural-gas hydrate in the sediments of the Bay of Bengal during the second Indian National Gas Hydrate Program (NGHP-02). Another highlight of the expedition was the unprecedented recovery of over 500 feet (152 meters) of sediments in pressure cores, which are specially designed to maintain sediments and their associated gas hydrates at the original sub-seafloor pressure conditions. After about 18 months in storage at the National Institute for Advanced Industrial Science and Technology (AIST) in Sapporo, Japan, five of the pressure cores were delivered to the USGS Woods Hole Coastal and Marine Science Center in March 2017. The pressure cores will be analyzed in the newly inaugurated USGS Hydrate Pressure Core Analysis Laboratory (HyPrCAL). This facility is the first in the U.S. to be designed for and dedicated to the analysis of pressure cores.
USGS Estimates 304 Trillion Cubic Feet of Natural Gas in the Bossier and Haynesville Formations of the U.S. Gulf Coast
April 13—The Bossier and Haynesville Formations of the onshore and State waters portion of the U.S. Gulf Coast contain estimated means of 4.0 billion barrels of oil, 304.4 trillion cubic feet of natural gas, and 1.9 billion barrels of natural-gas liquids, according to updated assessments by the USGS. These estimates, the largest continuous natural-gas assessment USGS has yet conducted, include petroleum in both conventional and continuous accumulations, and consist of undiscovered, technically recoverable resources. “As the USGS revisits many of the oil and gas basins of the United States, we continually find that technological revolutions of the past few years have truly been a game-changer in the amount of resources that are now technically recoverable," said Walter Guidroz, Program Coordinator of the USGS Energy Resources Program.
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