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USGS2019

Assessing beach and island habitat loss in the Chesapeake Bay and Delmarva coastal bay region, USA, through processing of Landsat TM and OLI imagery: A case study

Beaches and islands provide economic value to humans and critical habitat for breeding and foraging wildlife. These ecosystems, however, are being severely impacted by global climate change and sea level rise through increased erosion and frequency of inundation. The case study presented here aimed to document island loss in the Chesapeake Bay and Delmarva coastal bay region of the United States using image processing techniques within a GIS from 1986 to 2016. Satellite imagery from Landsat Thematic Mapper (TM) and Operational Land Imager (OLI) sensors were processed within ArcMap 10.5 to determine spatial and temporal trends in island and beach habitat. Calculation of unweighted Cohen’s Kappa showed that classified scenes were, on average, within the range of moderate agreement between the classified Landsat scenes and the validation imagery within Google Earth (0.539). Recommendations regarding existing beach habitat management and future supplementation were created based on these results. From 1986 to 2016, island area declined by over 1,200 hectares (ha) with agriculture/open field (all open vegetated spaces) declining by nearly 82% and beach, surprisingly, increasing nearly 2%. This study was the first to document Chesapeake Bay region-wide island loss beyond the mid-2000s. The accuracy of this study was limited slightly by the 30 m spatial resolution of the imagery used. This technique may be best suited for documenting trends on large islands and along the mainland coastline.

Maryland, Virginia↗

USGS2018

Executive summary. In Second State of the Carbon Cycle Report (SOCCR2): A Sustained Assessment Report

Central to life on Earth, carbon is essential to the molecular makeup of all living things and plays a key role in regulating global climate. To understand carbon’s role in these processes, researchers measure and evaluate carbon stocks and fluxes. A stock is the quantity of carbon contained in a pool or reservoir in the Earth system (e.g., carbon in forest trees), and a flux is the direction and rate of carbon’s transfer between pools (e.g., the movement of carbon from the atmosphere into forest trees during photosynthesis). This document, the Second State of the Carbon Cycle Report (SOCCR2), examines the patterns of carbon stocks and fluxes—collectively called the “carbon cycle.” Emphasis is given to these patterns in specific sectors (e.g., agriculture and energy) and ecosystems (e.g., forests and coastal waters) and to the response of the carbon cycle to human activity. The purpose of SOCCR2 is to assess the current state of the North American carbon cycle and to present recent advances in understanding the factors that influence it. Concentrating on North America—Canada, the United States, and Mexico—the report describes carbon cycling for air, land, inland waters (streams, rivers, lakes, and reservoirs), and coastal waters (see Figure ES.1, p. 23). The questions framing the publication A U.S. Carbon Cycle Science Plan (Michalak et al., 2011) inspired development of three slightly modified questions that guide SOCCR2’s content and focus on North America in a global context: How have natural processes and human actions affected the global carbon cycle on land, in the atmosphere, in the ocean and other aquatic systems, and at ecosystem interfaces (e.g., coastal, wetland, and urban-rural)? How have socioeconomic trends affected atmospheric levels of the primary carbon-containing gases, carbon dioxide (CO2) and methane (CH4)? How have species, ecosystems, natural resources, and human systems been impacted by increasing greenhouse gas (GHG) concentrations, associated changes in climate, and carbon management decisions and practices? SOCCR2 synthesizes the most recent understanding of carbon cycling in North America, assessing new carbon cycle findings and information, the state of knowledge regarding core methods used to study the carbon cycle, and future research needed to best inform carbon management and policy options. Focusing on scientific developments in the decade since the First State of the Carbon Cycle Report (SOCCR1; CCSP 2007), SOCCR2 summarizes the past, current, and projected state of carbon sources, sinks, and natural processes, as well as contributions by human activities. In addition to CO2 and CH4, the report sometimes discusses nitrous oxide (N2O), a GHG associated with activities and processes that affect fluxes of carbon gases.1 SOCCR2 also describes improvements in analysis tools; developments in decision support; and new insights into ecosystem carbon cycling, human causes of changes in the carbon cycle, and social science perspectives on carbon. Since publication of SOCCR1, coordinated research from agencies in the three North American countries has enabled innovative observational, analytical, and modeling capabilities to further advance understanding of the North American carbon cycle (see Appendix D: Carbon Measurement Approaches and Accounting Frameworks, p. 834). Some of the report’s main conclusions, based on the Key Findings of each chapter, are highlighted in Box ES.1, Main Findings of SOCCR2, p. 24.

Report↗

USGS2020

2018 and 2023 U. S. National Seismic Hazard Models

During 2017-2018, the National Seismic Hazard Model (NSHM) was updated by incorporating (1) new median ground motion models, new estimates of their epistemic uncertainties and aleatory variabilities, and new soil amplification factors for the central and eastern U.S., (2) amplification of long-period ground motions in deep sedimentary basins in the Los Angeles, San Francisco, Seattle, and Salt Lake City areas, (3) an updated seismicity catalog, which includes new earthquakes that occurred between 2012 and 2017, and (4) improved computer code and implementation details. Results show significantly increased ground shaking in many (but not all) locations across the central and eastern U.S., and increased ground shaking in the four urban areas (listed above) that overlie deep sedimentary basins in the western U.S. During 2019-2023, the NSHM will consider additional updates for the 2023 NSHM including: 3D simulations in urban areas of Los Angeles and Seattle, additional soil amplification models for other urban areas (e.g., eastern and southern coastal plains of the U.S., Reno, and Las Vegas), non-ergodic ground motion models that reconsider epistemic and aleatory uncertainty, topographic amplification, and new geological and geodetic models for faults. These maps will be considered by the Building Seismic Safety Council, American Society of Civil Engineers, and International Building Code committees for inclusion in upcoming building codes. Due to population growth, more people live and work in areas of moderate or high seismic hazard than ever before, leading to higher risk of undesirable consequences from future ground shaking.

conterminous United States↗

USGS2011

Comment on “Sea level rise shown to drive coastal erosion”

In a recent article ( Eos, Trans., AGU , February 8, 2000, p.55), Leatherman et al. [2000] state that they have confirmed an association between sea-level rise and coastal erosion. Applying their results to the New Jersey, Delaware, and Maryland coasts and using a projected sea-level rise, the authors predict that by 2050 the shoreline will recede 60 m, about two times the average beach width. However, Leatherman et al. [2000] have not convincingly quantified a relationship between sea-level rise and shoreline erosion.We do not agree with their rationale for subsetting their data, and they have not considered other explanations for a background erosion along the U.S. east coast. Furthermore, their future projections are not supported by their analyses.

Eos, Transactions, American Geophysical Union↗

USGS1980

Shallow, low-permeability reservoirs of northern Great Plains: Assessment of their natural gas resources.

Major resources of natural gas are entrapped in low-permeability, low-pressure reservoirs at depths less than 4,000 ft (1,200 m) in the northern Great Plains. This shallow gas is the product of the immature stage of hydrocarbon generation and is referred to as biogenic gas. Prospective low-permeability, gas-bearing reservoirs range in age from late Early to Late Cretaceous and include most of the section from the base of the Mowry Shale to the top of the Judith River Formation. For detailed examination, the potential reservoir section was divided into five intervals represented by one or more formations and their correlatives. The intervals selected correspond to (1) Mowry Shale, (2) Belle Fourche Shale and Greenhorn Formation, (3) Carlile Shale, (4) Niobrara and Telegrap Creek Formations and Eagle Sandstone, and (5) Claggett Shale and Judith River Formation and their equivalents. Within each interval, several different facies are developed. The following facies were identified and mapped for each interval: nonmarine rocks, coastal sandstones, shelf sandstones, siltstones, shales, and chalks. Two types of shelf sandstone were differentiated but generally not mapped separately because of lack of well log control. The "sand ridge" type has reservoir properties comparable to coastal sandstones and occurs as isolated tongues as much as 75 ft (23 m) thick. The second type of shelf sandstone is in beds commonly less than 1 in. (3 cm) thick which are interbedded with shale and contain a high content of allogenic silt- and clay-size material. It is impossible to differentiate these individual beds on conventional well logs. The siltstone and shale facies are grouped to ether because conventional logs cannot distinguish between these two rock types, particularly when they are interbedded. For future evaluation of natural gas resources from low-permeability reservoirs, it will be necessary to differentiate between the siltstone and shale facies and to identify individual beds, particularly very thin ones, within the shelf sandstone facies. Each facies contains distinct reservoir types, some of which are low in permeability. The most promising low-permeability reservoirs are developed in the shelf sandstone, siltstone, and chalk facies. Reservoirs within these facies are particularly attractive because they are enveloped by thick sequences of shale which serve as both a source and a seal for the gas. When naturally fractured, these shales also may be low-productivity gas reservoirs similar to the Devonian shales of the Appalachian basin. In addition, facies with low-permeability reservoirs are present over most of the study area when maps for all of the intervals are combined. Natural gas is produced from low-permeability reservoirs in the northern Great Plains in the southern part of western Canada. Established production covers an area of approximately 8,000 sq mi (20,700 sq km) where reported recoverable reserves average as much as 2 Bcf sq mi. Using these reserve data as an analog, the United States portion may contain resources of natural gas in excess of 100 Tcf. The volume of recoverable gas in the United States will depend on the development of improved recovery technology and higher gas prices relative to costs.

northern Great Plains↗

USGS2011

Evidence and implications of recent and projected climate change in Alaska's forest ecosystems

The structure and function of Alaska's forests have changed significantly in response to a changing climate, including alterations in species composition and climate feedbacks (e.g., carbon, radiation budgets) that have important regional societal consequences and human feedbacks to forest ecosystems. In this paper we present the first comprehensive synthesis of climate-change impacts on all forested ecosystems of Alaska, highlighting changes in the most critical biophysical factors of each region. We developed a conceptual framework describing climate drivers, biophysical factors and types of change to illustrate how the biophysical and social subsystems of Alaskan forests interact and respond directly and indirectly to a changing climate. We then identify the regional and global implications to the climate system and associated socio-economic impacts, as presented in the current literature. Projections of temperature and precipitation suggest wildfire will continue to be the dominant biophysical factor in the Interior-boreal forest, leading to shifts from conifer- to deciduous-dominated forests. Based on existing research, projected increases in temperature in the Southcentral- and Kenai-boreal forests will likely increase the frequency and severity of insect outbreaks and associated wildfires, and increase the probability of establishment by invasive plant species. In the Coastal-temperate forest region snow and ice is regarded as the dominant biophysical factor. With continued warming, hydrologic changes related to more rapidly melting glaciers and rising elevation of the winter snowline will alter discharge in many rivers, which will have important consequences for terrestrial and marine ecosystem productivity. These climate-related changes will affect plant species distribution and wildlife habitat, which have regional societal consequences, and trace-gas emissions and radiation budgets, which are globally important. Our conceptual framework facilitates assessment of current and future consequences of a changing climate, emphasizes regional differences in biophysical factors, and points to linkages that may exist but that currently lack supporting research. The framework also serves as a visual tool for resource managers and policy makers to develop regional and global management strategies and to inform policies related to climate mitigation and adaptation.

Alaska↗

USGS2009

Reconnaissance Assessment of the Potential for Roadside Dry Wells to Affect Water Quality on the Island of Hawai'i

The County of Hawai'i Department of Public Works (DPW) uses dry wells to dispose of stormwater runoff from roads. Recently, concern has been raised that water entering the dry wells may transport contaminants to groundwater and affect the quality of receiving waters. The DPW operates 2,052 dry wells. Compiling an inventory of these dry wells and sorting it on the basis of presence or absence of urbanization in the drainage area, distance between the bottom of the dry well and the water table, and proximity to receiving waters helps identify the dry wells having greatest potential to affect the quality of receiving waters so that future studies or mitigation efforts can focus on a smaller number of dry wells. The drainage areas of some DPW dry wells encompass urbanized areas, which could be a source of contaminants. Some dry wells penetrate close to or through the water table, eliminating or substantially reducing opportunities for contaminant attenuation between the ground surface and water table. Dry wells that have drainage areas that encompass urbanization, penetrate to near the water table, and are near the coast have the highest potential to affect the quality of coastal waters (this study did not consider specific sections of coastline that may be of greater concern than others). Some DPW dry wells, including a few that have drainage areas that encompass urbanization, lie within the areas contributing recharge (ACR) to drinking-water wells. Numerical groundwater modeling studies by previous investigators indicate that water infiltrating those dry wells could eventually be pumped at drinking-water wells. Dry wells that have a high potential for affecting coastal receiving waters or drinking-water wells can be the focus of studies to further understand the effect of the dry wells on the quality of receiving waters. Possible study approaches include sampling for contaminants at the dry well and receiving water, injecting and monitoring the movement of tracers, and numerical modeling. To fully assess whether dry wells actually pose a significant contamination threat to receiving waters, results from modeling or monitoring must be compared to limits for contaminant concentration at receiving waters. These limits are usually established by the agencies tasked with protecting those waters.

Scientific Investigations Report↗

USGS2015

The use of quantitative models in sea otter conservation

Sea otters are good indicators of ocean health. In addition, they are a keystone species, offering a stabilizing effect on ecosystem, controlling sea urchin populations that would otherwise inflict damage to kelp forest ecosystems. The kelp forest ecosystem is crucial for marine organisms and contains coastal erosion. With the concerns about the imperiled status of sea otter populations in California, Aleutian Archipelago and coastal areas of Russia and Japan, the last several years have shown growth of interest culturally and politically in the status and preservation of sea otter populations. Sea Otter Conservation brings together the vast knowledge of well-respected leaders in the field, offering insight into the more than 100 years of conservation and research that have resulted in recovery from near extinction. This publication assesses the issues influencing prospects for continued conservation and recovery of the sea otter populations and provides insight into how to handle future global changes.

Book chapter↗

USGS1947

Geology and ground-water resources of the island of Molokai, Hawaii

The island of Molokai is the fifth largest of the Hawaiian Islands, with an area of 250 square miles. It lies 25 miles southeast of Oahu, and 8.5 miles northwest of Maui. It consists of two principal parts, each a major volcanic mountain. East Molokai rises to 4,970 feet altitude. It is built largely of basaltic lavas, with a thin cap of andesites and a little trachyte. The volcanic rocks of East Molokai are named the East Molokai volcanic series, the basaltic part being separated as the lower member of the series, and the andesites and trachytes as the upper member. Large cinder cones and bulbous domes are associated with the lavas of the upper member. Thin beds of ash are present locally in both members. The lavas of the lower member are cut by innumerable dikes lying in two major rift zones trending eastward and northwestward. A large caldera, more than 4 miles long, and a smaller pit 0.8 mile across existed near the summit of the volcano. The rocks formed in and under the caldera are separated on plate 1 as the caldera complex. Stream erosion has cut large amphitheater-headed valleys into the northern coast of East Molokai, exposing the dikes and the caldera complex. West Molokai is lower than East Molokai, rising to 1,380 feet altitude. It was built by basaltic lavas erupted along rift zones trending southwestward and northwestward. Many of the flows were unusually fluid. The volcanic rocks of West Molokai Volcano are named the West Molokai volcanic series. Along its eastern side, the mountain is broken by a series of faults along which its eastern edge has been dropped downward. West Molokai Volcano became extinct earlier than East Molokai Volcano, and its flank is partly buried beneath lavas of East Molokai. Both volcanic mountains were built upward from the sea floor probably during Tertiary time. Following the close of volcanic activity stream erosion cut large canyons on East Molokai, but accomplished much less on drier West Molokai. Marine erosion attacked both parts of the island, producing high sea-cliffs on the windward coast. In late Tertiary or early Pleistocene time the island was submerged to a level at least 560 feet above the present shore line, then reemerged. Later shifts of sea level, probably partly resulting from Pleistocene glaciation and deglaciation, ranged from 300 feet below to 100 feet or more above present sea level. Marine deposits on the southern slope extend to an altitude of at least 200 feet. Eruption of the Kalaupapa basalt built a small lava cone at the foot of the northern cliff, forming Kalaupapa peninsula; and a small submarine eruption off the eastern end of Molokai built the Mokuhooniki tuff cone, the fragments of which now form Hooniki and Kanaha Islands. Deposition of marine and fluviatile sediments has built a series of narrow flats close to sea-level along the southern coast. Nearly the entire island is underlain, close to sea level, by ground water of the basal zone of saturation. Beneath West Molokai, the Hoolehua Plain between West and East Molokai, and the southern coastal area of East Molokai, the basal water is brackish. Beneath much of East Molokai, fresh basal water is obtainable. Small amounts of fresh water are perched at high levels in East Molokai by thin poorly permeable ash beds. Fresh water is confined at high levels in permeable compartments between poorly permeable dikes in the rift zones of East Molokai, and can be developed by tunnels. Projects to bring the abundant surface and ground water of the large wind ward valleys to the Hoolehua Plain are described. Future developments are suggested. All wells and water-development tunnels are described in tables.

Hawaii↗

USGS1991

Geologic controls on the formation and evolution of quaternary coastal deposits of the northern Gulf of Mexico

A study of the barrier islands and wetlands in the deltaic plain of Louisiana is presented. Its purpose was to document rapid changes and to learn more about the processes responsible and the geologic framework within which they operate. It included systematic collection and analysis of precision nearshore hydrographic data, high resolution seismic profiles, surface sediment samples, continuous vibracores, digital shoreline plots, records of storm overwash events, and analysis of tide gage records to quantify the rise in relative sea level. Results from these studies demonstrate that deltaic progradation, river channel switching, and subsequent rapid erosion accompanying the marine transgression are regular and predictable events along the Mississippi River delta plain and will likely continue in the future. Mitigation measures, such as shoreline nourishment and barrier restoration, that mimic the natural processes may slow the land loss.

Conference Paper↗

USGS2020

Climate- and disturbance-driven changes in subsistence berries in coastal Alaska: Indigenous knowledge to inform ecological inference

Berry-producing plants are a key subsistence resource in Indigenous Alaskan communities. High-latitude coastal regions are particularly impacted by global climate change due to their location at the land-sea ecotone subjecting them to terrestrial stressors as well as shifts in ocean dynamics. While vegetation changes have been documented for the subarctic coastal region of Alaska, we know little about permafrost underlain portions of the landscape that support berry communities. To fill this gap surveys were administered in four communities within the Yukon-Kuskokwim Delta, to identify observations of changes in berry resources and integrate Indigenous Knowledge of drivers of changes with climate projections. We found that while most participants agreed on several observed changes and drivers, many important differences were identified at the community level. Regional consensus can be used in combination with climate projections to forecast potential future impacts to berry resources while distinctions at the community level can help us to untangle local scale disturbances.

Alaska↗

USGS1971

Ground-water resources: Cumberland County, New Jersey

Cumberland County is located in the Atlantic Coastal Plain physiographic province along the northeastern shore of Delaware Bay in Southwestern New Jersey. An average annual hydrologic budget was computed for Cumberland County. Water gains are: precipitation, 1,050 mgd (million gallons per day); surface-water inflow, 142 mgd; ground-water inflow negligible. Water losses are: evapotranspiration, 685 mgd; surface-water outflow, 370 mgd; ground-water outflow, 137 mgd. Unconsolidated and semiconsolidated Coastal Plain sediments, 2,500 to 4,500 feet thick, and ranging in age from Cretaceous to Holocene, consist of layers of clay, silt, sand and gravel. Aquifers composed mainly of sand and gravel occur in the Potomac Group and Raritan and Magothy Formations, the Wenonah Formation and Mount Laurel Sand, the Piney Point Formation, and the Kirkwood Formation and Cohansey Sand. Aquifers in the Potomac-Raritan-Magothy sequence contain saline water and are not currently utilized in Cumberland County. However, they may be utilized in the future for underground storage of fresh water, or possibly other uses when more is known about this aquifer system. The aquifer in the Wenonah Formation and Mount Laurel Sand is not presently utilized in Cumberland County. It is probably suitable for future development, however of wells yielding as much as 300 gpm (gallons per minute) of good quality water in the northern part of the county. The Piney Point Formation is tapped in Cumberland County by only a few wells; each of these generally yield less than 100 gpm. Additional small supplies can be developed from this aquifer. Water from this aquifer requires little or no treatment for domestic use. Two principal aquifers occur in the Kirkwood Formation and Cohansey Sand: (1) the lower Kirkwood aquifer and (2) the Cohansey-Kirkwood aquifer. Most wells tapping the lower Kirkwood aquifer yield less than 50 gpm but are capable of yielding as much as 400 gpm. Wells in the lower Kirkwood range in depth from 200 to 370 feet. The Cohansey-Kirkwood aquifer is the shallowest and most important source of ground-water in the county but is highly susceptible to surface contamination. This aquifer is highly permeable; analysis of data from two pumping tests indicates permeabilities of 1,200 and 2,700 gpm per square foot. It generally yields large supplies of water (300 to 1,200 gpm) to wells from depths of less than 180 feet. Water in the Cohansey-Kirkwood aquifer is characterized by 1mv dissolved-solids content (63 mg/l, median), low hardness (21 mg/l, median), and low pH values (5.5 pH units, median). Water use in Cumberland County varies and is highly seasonal, mainly because of increasing requirements for irrigation and the food processing industries in the county. In 1964 seasonal use ranged from 27 mgd in March to 145 mgd in August. This is much higher than withdrawals in neighboring Salem and Cape May Counties. In 1964 withdrawals in Cumberland County averaged about 51 mgd; almost all of this, 49.4 mgd, was from ground-water supplies. The total annual water use in 1964 according to type of use was: for public supply, 10.6 mgd; for industrial uses, 19.0 mgd; irrigation, 15.4 mgd; suburban, rural, residential, institutional, farm, and commercial, 5.9 mgd.

New Jersey↗

USGS2013

Geographic range and structure of cryptic genetic diversity among Pacific North American populations of the non-native amphipod Grandidierella japonica

Reconstructing the invasion history of aquatic invasive species can enhance understanding of invasion risks by recognizing areas most susceptible to invasion and forecasting future spread based on past patterns of population expansion. Here we reconstruct the invasion history of the Japanese amphipod Grandidierella japonica Stephensen 1938 combining information from historical collection data with molecular genetic data to better understand post-invasion range expansion and anthropogenic connectivity across the Pacific coast of North America. Compilation of collection data from bays and estuaries of the Pacific North American coast show many new localities have been colonized in the last two decades, moving outward from harbors and bays with high commercial traffic into smaller coastal locations dominated by local recreational traffic. DNA barcode sequence data for G. japonica reveals two distinct clades: one found in San Francisco Bay and sites to the north, and one also found in San Francisco Bay and sites to the south. The two clades differ by an average 7.28 % genetic distance, large enough to consider these invasive amphipods two separate species. Both northern and southern clades exhibit low levels of genetic diversity, suggesting a single introduction event for each. The presence of cryptic diversity within this invasive amphipod highlights the need for more extensive study of the invasive and native populations of aquatic invasive invertebrates to address questions of taxonomy, diversity, and invasion history.

California, Oregon, Washington↗

USGS2006

Potential effects of elevated atmospheric carbon dioxide (CO 2 ) on coastal wetlands

Carbon dioxide (CO 2 ) concentration in the atmosphere has steadily increased from 280 parts per million (ppm) in preindustrial times to 381 ppm today and is predicted by some models to double within the next century. Some of the important pathways whereby changes in atmospheric CO 2 may impact coastal wetlands include changes in temperature, rainfall, and hurricane intensity ( fig. 1 ). Increases in CO 2 can contribute to global warming, which may (1) accelerate sea-level rise through melting of polar ice fields and steric expansion of oceans, (2) alter rainfall patterns and salinity regimes, and (3) change the intensity and frequency of tropical storms and hurricanes. Sea-level rise combined with changes in storm activity may affect erosion and sedimentation rates and patterns in coastal wetlands and maintenance of soil elevations. Feedback loops between plant growth and hydroedaphic conditions also contribute to maintenance of marsh elevations through accumulation of organic matter. Although increasing CO 2 concentration may contribute to global warming and climate changes, it may also have a direct impact on plant growth and development by stimulating photosynthesis or improving water use efficiency. Scientists with the U.S. Geological Survey are examining responses of wetland plants to elevated CO 2 concentration and other factors. This research will lead to a better understanding of future changes in marsh species composition, successional rates and patterns, ecological functioning, and vulnerability to sea-level rise and other global change factors.

Fact Sheet↗

USGS2004

Hazard analysis of landslides triggered by Typhoon Chata’an on July 2, 2002, in Chuuk State, Federated States of Micronesia

More than 250 landslides were triggered across the eastern volcanic islands of Chuuk State in the Federated States of Micronesia by torrential rainfall from tropical storm Chata’an on July 2, 2002. Landslides triggered during nearly 20 inches of rainfall in less than 24 hours caused 43 fatalities and the destruction or damage of 231 structures, including homes, schools, community centers, and medical dispensaries. Landslides also buried roads, crops, and water supplies. The landslides ranged in volume from a few cubic meters to more than 1 million cubic meters. Most of the failures began as slumps and transformed into debris ﬂows, some of which traveled several hundred meters across coastal ﬂatlands into populated areas. A landslide-inventory map produced after the storm shows that the island of Tonoas had the largest area affected by landslides, although the islands of Weno, Fefan, Etten, Uman, Siis, Udot, Eot, and Fanapanges also had signiﬁcant landslides. Based on observations since the storm, we estimate the continuing hazard from landslides triggered by Chata’an to be relatively low. However, tropical storms and typhoons similar to Chata’an frequently develop in Micronesia and are likely to affect the islands of Chuuk in the future. To assess the landslide hazard from future tropical storms, we produced a hazard map that identiﬁes landslide-source areas of high, moderate, and low hazard. This map can be used to identify relatively safe areas for relocating structures or establishing areas where people could gather for shelter in relative safety during future typhoons or tropical storms similar to Chata’an.

Chuuk State↗

USGS2023

Gulf Islands National Seashore regional sediment budget research and data needs—Workshop series summary

Executive Summary The National Park Service (NPS), in collaboration with the U.S. Geological Survey (USGS), recognizes the need to quantify the sediment budget of the barrier islands within the Gulf Islands National Seashore (GINS) to understand the coastal processes affecting island resiliency. To achieve this goal, identifying and quantifying the physical parameters that drive long-term change is necessary to model the processes that are both generative and terminal in island evolution and capture island response to long-term human alteration and climatic patterns. For example, measuring change across periods of storminess is more effective at assessing island resiliency than measuring change resulting from a single storm impact. Understanding changes to the physical environment over time is key to successfully predicting island responses to future storm impacts, human alteration, and sea-level rise and is necessary for effective decision making and management response. Yet, the diversity of factors affecting natural and cultural resources necessitates a strategic approach to data collection priorities that can inform sediment budget quantification and integrated resource management. This study sought to advance sediment budget modeling efforts by conducting a “Needs Assessment Workshop” at the GINS. The purpose of the workshop was to identify and prioritize the specific research and data needs regarding the sediment budget at the GINS that can enhance the NPS efforts to conserve the islands’ natural resources, cultural resources, and the facilities and infrastructure that support both conservation and visitor use of those resources. This effort explored two research questions: (1) “what research and data needs exist for the sediment budget at Gulf Islands National Seashore” (research question 1) and (2) “how can research to address these needs capitalize on regional partnerships to advance natural and cultural resource conservation at Gulf Islands National Seashore” (research question 2)? The workshop was conducted virtually in a two-part, two-day series. The workshop series was organized by researchers from North Carolina State University in collaboration with NPS and USGS staff and was facilitated by National Oceanographic and Atmospheric Administration staff. The workshop series (two paired, sequential, partial-day workshops) addressed two target audiences: (1) NPS and USGS staff (April workshop) and (2) regional Federal, State, county, and nongovernmental organization staff, including NPS and USGS staff (May workshop). A total of four workshop sessions were held, comprising two sessions with each target audience. The workshop series intended to identify sediment management research and data needs that could enhance natural and cultural resource stewardship at the GINS. One objective was to share information about regional sediment transport and management, available sediment management plans, and predictive modeling capabilities, including geomorphologic and hydrodynamic predictive models. This information was shared through a series of presentations by park managers and NPS and USGS researchers that identified park issues and available capabilities and data. The second objective was to elicit research and data needs, with a primary goal of assessing the importance and urgency of the identified needs. This assessment was partly determined by requesting that the workshop participants identify and prioritize research themes through polls, comments, and discussion. The polls explicitly asked participants to qualitatively evaluate the importance (not at all, slightly, somewhat, very, or extremely) and urgency (not at all, slightly, somewhat, very, or extremely) of the thematically grouped research and data needs. These evaluations were plotted and shared during the workshop to visualize how the relative importance ( x -axis) and relative urgency ( y -axis) of each “need,” relative to other needs, to identify the most necessary (importance) and time-sensitive (urgent) items, thereby allowing an enhanced, holistic understanding of the sediment budget at GINS. Results of the poll are published as a USGS data release. The assessment results revealed that the most important and urgent research and data needs included mapping (for example, elevation, habitat, and cultural resources), a regional sediment budget and management plan, and the dynamic modeling of sediment processes. During the workshop, these issues were visualized using scatter plots to demonstrate the relative importance and urgency of each theme, provide descriptive statistics, and elicit discussion. This format of iterative presentation, discussion, and prioritization allowed the project team to effectively accomplish their objective of identifying important and urgent research needs for natural and cultural resource stewardship at the GINS. Through the workshop, it was determined that expanded communication with the broader research community was needed to coordinate research activities and streamline potential funding opportunities and that research and policy should be integrated through a structured decision-making process. At the conclusion of the workshop, an administered poll showed that the presentations effectively identified data and research needs and that the goals of the workshop were achieved. The results suggest that this type of needs-assessment workshop can effectively identify existing research capabilities and data, determine and prioritize research and data needs, and address how these efforts can use regional partnerships to aid natural and cultural resource conservation and management at National Parks.

Florida, Mississippi↗

USGS1976

Groundwater from Lower Cretaceous rocks in Kansas

Sandstones in Lower Cretaceous rocks contain supplies, of water that may be adequate to meet increasing present and future demands for supplemental municipal and domestic use in central and western Kansas. An estimated 70 to 80 million acre-feet (86,000 to 99,000 cubic hectometers) of water containing less than 1,000 milligrams per liter dissolved solids may be acceptable for use at the present (1976). An additional 10 to 15 million acre-feet (12,000 to 18,000 cubic hectometers) containing 1,000 to 3,000 milligrams per liter dissolved solids is estimated to be available for use in the future with appropriate desalinization. Lower Cretaceous rocks crop out from Washington County on the north to Comanche County on-the south. The rocks dip from a structural high in the southwest part of the State to structural lows in the northwest and north-central part. Depth below land surface increases generally northwestward to about 2,600 feet (790 meters); thickness of the rocks increases westward, nearly zero to about 850 feet (260 meters). The rocks consist chiefly of marine to nonmarine shale and silt- stone interbedded with coastal to deltaic sandstone. The interbedded sandstone, which composes about one-third of the rocks, consists of one or more lenses that thicken westward to about 400 feet (120 meters) in the central part of western Kansas. The yield of water to individual wells is related to areal extent, thickness, and interconnection of the sand lenses and to grain size and cementation of the sand. Large amounts of water may be pumped by wells where loosely cemented sand lenses are interconnected. Wells commonly yield adequate supplies for domestic and stock use; reported yields from municipal and irrigation wells range from about 100 to 2,000 gallons per minute (6 to 125 liters per second). Recharge to the Lower Cretaceous-rocks occurs in the area of outcrop and from hydraulically connected saturated Cenozoic rocks, especially in the southern part of the State. Movement of water is principally northeastward from areas of recharge to areas of discharge where streams intersect the sandstone outcrops. Water in the sandstone aquifers commonly is confined between beds of relatively impermeable shale, causing water in wells to rise above the top of the aquifer. Water levels fluctuate in response to changes in atmospheric pressure, recharge, and discharge; greatest fluctuations result from discharge to wells for municipal and irrigation use. Progressive declines in water levels have occurred where irrigation withdrawals exceed recharge. Calcium bicarbonate water is dominant near recharge areas; mixed sodium and calcium bicarbonate water and sodium chloride water become successively dominant as the water moves downgradient from the recharge areas. The quality of water ranges from fresh to very saline (less than 1.000 to 35,000 milligrams per liter dissolved solids). In the areas of generally fresh water, localized areas of calcium sulfate water result from solution of gypsum in the Kiowa Formation, and areas of sodium chloride water result from contamination by oil-field brines.

Open-File Report↗

USGS2008

Sandy signs of a tsunami's onshore depth and speed

Tsunamis rank among the most devastating and unpredictable natural hazards to affect coastal areas. Just 3 years ago, in December 2004, the Indian Ocean tsunami caused more than 225,000 deaths. Like many extreme events, however, destructive tsunamis strike rarely enough that written records span too little time to quantify tsunami hazard and risk. Tsunami deposits preserved in the geologic record have been used to extend the record of tsunami occurrence but not the magnitude of past events. To quantify tsunami hazard further, we asked the following question: Can ancient deposits also provide guidance on the expectable water depths and speeds for future tsunamis?

Eos, Transactions, American Geophysical Union↗