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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-quality data toward efforts such as public education of flood risk, flood inundation mapping, flood frequency computations, indirect streamflow measurement, and hazard assessments. This manual presents guidance for skilled high-water mark identification, including marks left behind in natural and man-made environments by tranquil and rapid flowing water. This manual also presents pitfalls and challenges associated with various types of flood evidence that help hydrographers identify the best high-water marks and assess the uncertainty associated with a given mark. Proficient high-water mark data collection contributes to better understanding of the flooding process and reduces risk through greater ability to estimate flood probability. The U.S. Geological Survey, operating the Nation’s premier water data collection network, encourages readers of this manual to familiarize themselves with the art and science of high-water mark collection. The U.S. Geological survey maintains a national database at http://water.usgs.gov/floods/FEV/ that includes high-water mark information for many flood events, and local U.S. Geological Survey Water Science Centers can provide information to interested readers about participation in data collection and flood documentation efforts as volunteers or observers.

Techniques and Methods↗

Integrated geoscience studies in the Greater Yellowstone Area - Volcanic, tectonic, and hydrothermal processes in the Yellowstone geoecosystem

Yellowstone National Park, rimmed by a crescent of older mountainous terrain, has at its core the Quaternary Yellowstone Plateau, an undulating landscape shaped by forces of volcanism, tectonism, and later glaciation. Its spectacular hydrothermal systems cap this landscape. From 1997 through 2003, the United States Geological Survey Mineral Resources Program conducted a multidisciplinary project of Yellowstone National Park entitled Integrated Geoscience Studies of the Greater Yellowstone Area, building on a 130-year foundation of extensive field studies (including the Hayden survey of 1871, the Hague surveys of the 1880s through 1896, the studies of Iddings, Allen, and Day during the 1920s, and NASA-supported studies starting in the 1970s—now summarized in USGS Professional Paper 729 A through G) in this geologically dynamic terrain. The project applied a broad range of scientific disciplines and state-of-the-art technologies targeted to improve stewardship of the unique natural resources of Yellowstone and enable the National Park Service to effectively manage resources, protect park visitors from geologic hazards, and better educate the public on geologic processes and resources. This project combined a variety of data sets in characterizing the surficial and subsurface chemistry, mineralogy, geology, geophysics, and hydrothermal systems in various parts of the park. The sixteen chapters presented herein in USGS Professional Paper 1717, Integrated Geoscience Studies in the Greater Yellowstone Area—Volcanic, Tectonic, and Hydrothermal Processes in the Yellowstone Geoecosystem , can be divided into four major topical areas: (1) geologic studies, (2) Yellowstone Lake studies, (3) geochemical studies, and (4) geophysical studies. The geologic studies include a paper by Ken Pierce and others on the influence of the Yellowstone hotspot on landscape formation, the ecological effects of the hotspot, and the human experience and human geography of the greater Yellowstone ecosystem as influenced by the Yellowstone hotspot. Another paper by Paul Carrara describes the recent movement of a large landslide block dated by tree-ring analyses in the Tower Falls area. The section under Yellowstone Lake studies begins with a classic paper by J. David Love and others on ancestral Lake Yellowstone. Other papers in this section include results and interpretation of the high-resolution bathymetric, seismic reflection, and submersible studies by Lisa Morgan and others. Ken Pierce and others describe results from their studies of shorelines along Yellowstone Lake and their interpretation of inflation-deflation cycles, tilting, and faulting in the Yellowstone caldera. The influence of sublacustrine hydrothermal vent fluids on the geochemistry of Yellowstone Lake is described by Laurie Balistrieri and others. In Pat Shanks and others’ chapter, hydrothermal reactions, stable-isotope systematics, sinter deposition, and spire formation are related to the geochemistry of sublacustrine hydrothermal deposits in Yellowstone Lake. The geochemical studies section considers park-wide geochemical systems in Yellowstone National Park. In Bob Rye and Alfred Truesdell’s paper, the question of recharge to the deep thermal reservoir underlying the geysers and hot springs of Yellowstone National Park is discussed. Irving Friedman and Dan Norton report on the chloride flux emissions from Yellowstone in their paper questioning whether Yellowstone is losing its steam. Wildlife issues as addressed by examining trace-element and stable-isotope geochemistry are discussed in a chapter by Maurice Chaffee and others. In another chapter by Chaffee and others, natural and anthropogenic anomalies and their potential impact on the environment using geochemistry is reported. Pam Gemery-Hill and others present geochemical data for selected rivers, lake waters, hydrothermal vents, and subaerial geysers for the time interval of 1996–2004. The life cycle of gold deposits near the northeast corner of the park is discussed by Brad Van Gosen. Under the geophysical studies segment, Ray Kokaly and others use AVIRIS (Airborne Visible and Infrared Spectroscopy) data to map vegetation cover and microbial communities in Yellowstone National Park. Eric Livo and others report their results using AVIRIS data on hydrothermally altered rock and hot-spring deposits. In his final paper following a half century of scientific research, Irving Friedman presents data on monitoring changes in geothermal activity at Norris Geyser Basin using satellite telemetry. These papers summarize a near-decade-long effort by the USGS from the late 1990s to mid-2000s. In 2001, the USGS in cooperation with the National Park Service (Yellowstone National Park) and the University of Utah established the Yellowstone Volcano Observatory, the 5th volcano observatory in the United States.

Idaho, Montana, Wyoming↗

Proceedings of the 9th U.S.-Japan natural resources panel for earthquake research

Introduction The UJNR Panel on Earthquake Research promotes advanced study toward a more fundamental understanding of the earthquake process and hazard estimation. The Ninth Joint meeting was extremely beneficial in furthering cooperation and deepening understanding of problems common to both the U.S. and Japan. The meeting included productive exchanges of information on approaches to systematic observation and modeling of earthquake processes. Regarding the earthquake and tsunami of March 2011 off the Pacific coast of Tohoku, the Panel recognizes that further efforts are necessary to achieve our common goal of reducing earthquake risk through close collaboration and focused discussions at the 10th UJNR meeting. We look forward to continued cooperation on issues involving the densification of observation networks and the open exchange of data among scientific communities. We recognize the importance of making information publicly available in a timely manner. We also recognize the importance of information exchange on research policy and strategies, including the frameworks of research organizations. Areas of Cooperation –Specific areas of earthquake research where cooperative research between the U.S. and Japan may lead to significant advancement include, but are not limited to: –Probabilistic earthquake and tsunami hazard estimation, including extraordinarily large earthquakes, both in our respective countries and worldwide, incorporating knowledge of current and past behavior, and physics based computational models; –Real-time information from seismic, geodetic and strain measurements, including borehole strainmeters and seafloor observations using offshore cabled networks; –Technologies for measuring crustal deformation; –Early warning technologies for earthquakes and tsunamis; Studies of recurrence of large and extraordinary large earthquakes using paleoseismic, paleotsunami, geodetic and seismic methods; –Laboratory, theoretical and in situ studies of fault-zone processes; –Studies of episodic tremor and slow slip events using seismic, geodetic, and borehole strain measurements, and simulation techniques; –Systematic studies of earthquake predictability through rigorously evaluated scientific prediction experiments and robust databases; –Studies of near-source ground motions, geological effects and the response of engineered structures. The Panel strongly urges that the appropriate agencies in the U.S. and Japan that are represented on this panel work together with the academic sector to support and coordinate scientific work in these areas of cooperation. The Panel recognizes the importance of promoting the exchange of scientific personnel, exchange of data, and fundamental studies to advance progress in earthquake research. The U.S. and Japan should promote these exchanges throughout the world. The Panel endorses continuation of these activities.

Open-File Report↗

The Hawaiian Volcano Observatory: A natural laboratory for studying basaltic volcanism

In the beginning of the 20th century, geologist Thomas A. Jaggar, Jr., argued that, to fully understand volcanic and associated hazards, the expeditionary mode of studying eruptions only after they occurred was inadequate. Instead, he fervently advocated the use of permanent observatories to record and measure volcanic phenomena—at and below the surface—before, during, and after eruptions to obtain the basic scientific information needed to protect people and property from volcanic hazards. With the crucial early help of American volcanologist Frank Alvord Perret and the Hawaiian business community, the Hawaiian Volcano Observatory (HVO) was established in 1912, and Jaggar’s vision became reality. From its inception, HVO’s mission has centered on several goals: (1) measuring and documenting the seismic, eruptive, and geodetic processes of active Hawaiian volcanoes (principally Kīlauea and Mauna Loa); (2) geological mapping and dating of deposits to reconstruct volcanic histories, understand island evolution, and determine eruptive frequencies and volcanic hazards; (3) systematically collecting eruptive products, including gases, for laboratory analysis; and (4) widely disseminating observatory-acquired data and analysis, reports, and hazard warnings to the global scientific community, emergency-management authorities, news media, and the public. The long-term focus on these goals by HVO scientists, in collaboration with investigators from many other organizations, continues to fulfill Jaggar’s career-long vision of reducing risks from volcanic and earthquake hazards across the globe. This chapter summarizes HVO’s history and some of the scientific achievements made possible by this permanent observatory over the past century as it grew from a small wooden structure with only a small staff and few instruments to a modern, well-staffed, world-class facility with state-of-the-art monitoring networks that constantly track volcanic and earthquake activity. The many successes of HVO, from improving basic knowledge about basaltic volcanism to providing hands-on experience and training for hundreds of scientists and students and serving as the testing ground for new instruments and technologies, stem directly from the acquisition, integration, and analysis of multiple datasets that span many decades of observations of frequent eruptive activity. HVO’s history of the compilation, interpretation, and communication of long-term volcano monitoring and eruption data (for instance, seismic, geodetic, and petrologic-geochemical data and detailed eruption chronologies) is perhaps unparalleled in the world community of volcano observatories. The discussion and conclusions drawn in this chapter, which emphasize developments since the 75th anniversary of HVO in 1987, are general and retrospective and are intended to provide context for the more detailed, topically focused chapters of this volume.

Hawaii↗

Zinc hazards to plants and animals with emphasis on fishery and wildlife resources

Ecological and toxicological aspects of zinc in the environment are reviewed with emphasis on natural resources. Subtopics include sources and uses; chemical and biochemical properties; carcinogenicity, mutagenicity, teratogenicity; background concentrations in biological and nonbiological compartments; effects of zinc deficiency; toxic and sublethal effects on terrestrial plants and invertebrates, aquatic organisms, birds, and mammals; and recommendations for the protection of sensitive resources.

Book chapter↗

Mapping vulnerability to disasters in Latin America and the Caribbean, 1900–2007

The vulnerability of a population and its infrastructure to disastrous events is a factor of both the probability of a hazardous event occurring and the community's ability to cope with the resulting impacts. Therefore, the ability to accurately identify vulnerable populations and places in order to prepare for future hazards is of critical importance for disaster mitigation programs. This project created maps of higher spatial resolution of vulnerability to disaster in Latin America and the Caribbean from 1900 to 2007 by mapping disaster data by first-level administrative boundaries with the objective of identifying geographic trends in regional occurrences of disasters and vulnerable populations. The method of mapping by administrative level is an improvement on displaying and analyzing disasters at the country level and shows the relative intensity of vulnerability within and between countries in the region. Disaster mapping at the country level produces only a basic view of which countries experience various types of natural disasters. Through disaggregation, the data show which geographic areas of these countries, including populated areas, are historically most susceptible to different hazard types.

Open-File Report↗

Seamless numerical simulation of a hazard cascade in which a landslide triggers a dam-breach flood and consequent debris flow

Numerical simulations of hazard cascades downstream from moraine-dammed lakes commonly must specify linkages between models of discrete processes such as wave overtopping, dam breaching, erosion, and downstream floods or debris flows. Such linkages can be rather arbitrary and can detract from the ability to accurately conserve mass and momentum during complex sequences of events. Here we describe an alternative methodology in which we use high-resolution lidar topography and 2-D, two-phase conservation laws to seamlessly simulate all stages of a hazard-cascade that culminates in a debris flow. Our simulations employ our depth-integrated numerical model D-Claw to evaluate hazards from prospective breaching of a moraine dam that impounds Carver Lake on the eastern flank of South Sister volcano in central Oregon, USA. We simulate a “worst-case scenario” sequence of events that begins with a hypothetical 1.6 million m3 landslide that originates near the summit of South Sister and enters Carver Lake. Wave generation and displacement of lake water then leads to dam overtopping, breach erosion, and a downstream debris flow that funnels into Whychus Creek and eventually reaches the community of Sisters, Oregon, about 20 km away. Notably, our simulations predict that much of the debris is directed away from Sisters as a result of natural avulsion and flow diversion that occurs near the head of a low-gradient alluvial fan upstream from Sisters. Consequently, predicted hazards to downtown Sisters are less severe than those predicted by 1-D shallow-water simulations of a Carver Lake dam breach that were performed in the 1980s.

Conference Paper↗

Reconnaissance engineering geology of Sitka and vicinity, Alaska, with emphasis on evaluation of earthquake and other geologic hazards

A program to study the engineering geology of most of the larger Alaska coastal communities and to evaluate their earthquake and other geologic hazards was started following the 1964 Alaska earthquake; this report about Sitka and vicinity is a product of that program. Field-study methods were of a reconnaissance nature, and thus the interpretations in the report are subject to revision as further information becomes available. This report can provide broad geologic guidelines for planners and engineers during preparation of land-use plans. The use of this information should lead to minimizing future loss of life and property due to geologic hazards, especially during very large earthquakes. Landscape of Sitka and surrounding area is characterized by numerous islands and a narrow strip of gently rolling ground adjacent to rugged mountains; steep valleys and some fiords cut sharply into the mountains. A few valley floors are wide and flat and grade into moderate-sized deltas. Glaciers throughout southeastern Alaska and elsewhere became vastly enlarged during the Pleistocene Epoch. The Sitka area presumably was covered by ice several times; glaciers deeply eroded some valleys and removed fractured bedrock along some faults. The last major deglaciation occurred sometime before 10,000 years ago. Crustal rebound believed to be related to glacial melting caused land emergence at Sitka of at least 35 feet (10.7 m) relative to present sea level. Bedrock at Sitka and vicinity is composed mostly of bedded, hard, dense graywacke and some argillite. Beds strike predominantly northwest and are vertical or steeply dipping. Locally, bedded rocks are cut by dikes of fine-grained igneous rock. Host bedrock is of Jurassic and Cretaceous age. Eight types of surficial deposits of Quaternary age were recognized. Below altitudes of 3S feet (10.7 m), the dominant deposits are those of modern and elevated shores and deltas; at higher altitudes, widespread muskeg overlies a mantle of volcanic ash which commonly overlies glacial drift. Alluvial deposits are minor. Man-emplaced embankment fill, chiefly sandy gravel, covers many muskeg and former offshore areas; quarried blocks of graywacke are placed to form breakwaters and to edge large areas of embankment fill and modified ground. The geologic structure of the area is known only in general outlines. Most bedded Mesozoic rocks probably are part of broad northwest-trending complexes of anticlines and synclines. Intrusion of large bodies of plutonic igneous rocks occurred in Tertiary and Cretaceous time. Extensive faulting is suggested by the numerous linear to gently curving patterns of some fiords, lakes, and valleys, and by a group of Holocene volcanoes and cinder cones. Two major northwest-striking fault zones are most prominent: (1) the apparently inactive Chichagof-Sitka fault, about 2.5 miles (4.0 km) northeast of Sitka, and {2) part of the active 800-mile- (1,200-km) long Fairweather-Queen Charlotte Islands fault system, lying about 30 miles (48 km) southwest of the city. Many earthquakes have been reported as felt at Sitka since 1832, when good records were first maintained; several shocks were very strong, but none of them caused severe damage. The closest major earthquake (magnitude about 7.3) causing some damage to the city occurred July 30, 1972, and had an epicenter about 30 miles (48 km) to the southwest. Movement along the Fairweather-Queen Charlotte Islands fault system apparently caused most of the earthquakes felt at Sitka. The probability of destructive earthquakes at Sitka is unknown. The tectonics of the region and the seismic record suggest that sometime in the future an earthquake of a magnitude of about 8 and related to the Fairweather-Queen Charlotte Islands fault system probably will occur in or near the area. Effects from some nearby major earthquakes could cause substantial damage at Sitka. Eight possible effects are as follows: 1. Sudden dis

Open-File Report↗

Geologic map of the greater Portland metropolitan area and surrounding region, Oregon and Washington

The Portland-Vancouver-Hillsboro Metropolitan Area (metro area) has great scenic, natural, and cultural resources and is the major economic hub of Oregon. The metro area is subject to a variety of geologic hazards. Underthrusting of the oceanic plate along the Cascadia plate boundary fault, or megathrust, deforms the leading edge of North America and produces earthquakes on the megathrust and in the overlying plate. Rising magma from the deeper parts of the subduction zone produces active volcanoes that form the Cascades Arc, including Mount Hood and Mount St. Helens visible from Portland. Both volcanism and strong ground-shaking from earthquakes have impacted the metro area, most recently in the 1980 eruptions of Mount St. Helens and the 1993 magnitude (M) 5.7 Scotts Mills earthquake. Great offshore earthquakes as large as M 9 on the Cascadia megathrust have shaken the metro area every 500 years or so, most recently in 1700. Giant floods have inundated the metro area, from the ice age Missoula floods about 20,000 to 15,000 years ago to the flood generated by collapse of the Bridge of the Gods landslide dam on the Columbia River around 1421–1447 A.D. Geologic resources of the metro area include the southern part of the Mist Natural Gas Storage Field in the northwest corner of the map area, the Columbia South Shore Well Field aquifer in the Portland Basin, the Columbia River Basalt aquifer of the Tualatin Basin, and the Tualatin Basin Aquifer Storage and Recovery projects. The metro area includes several well-known American Viticultural Areas in the western part of the map area and numerous transportation, electrical transmission, and pipeline corridors. We created this map to provide a uniform, modern geologic database for the greater Portland metro area to better understand its tectonic setting, active faults, volcanoes, landslide hazards, and distribution of geologic materials and resources. Information in this database will be used to improve seismic hazard and resource assessments in this economically important region. NOTE: The sheet 1 map was divided into two parts—sheet 1 (north) and sheet 1 (south)—to facilitate printing and plotting the map.

Oregon, Washington↗

Worth of data and natural disaster insurance

The Federal Government in the past has provided medical and economic aid to victims of earthquakes and floods. However, regulating the use of hazard-prone areas would probably be more efficient. One way to implement such land use regulation is through the national flood and earthquake insurance program. Because insurance firms base their premium rates on available information, the benefits from additional data used to improve parameter estimates of the probability distribution (governing actual disaster events) can be computed by computing changes in the premiums as a function of additional data. An insurance firm is assumed to set rates so as to trade off penalties of overestimation and underestimation of expected damages. A Bayesian preposterior analysis is applied to determine the worth of additional data, as measured by changes in consumers’ surplus, by examining the effects of changes in premiums as a function of a longer hydrologic record.

Water Resources Research↗

The National Volcano Early Warning System (NVEWS)

The National Volcano Early Warning System (NVEWS) is a proposed national-scale effort by the U.S. Geological Survey (USGS) Volcano Hazards Program and its affiliated partners in the Consortium of U.S. Volcano Observatories (CUSVO) ( http://www.cusvo.org ) to ensure that volcanoes are monitored at a level commensurate with the threats they pose. Roughly half of the Nation’s 169 young volcanoes are dangerous because of the manner in which they erupt and the communities and infrastructure within their destructive reach. Most U.S. volcanoes are located on sparsely populated Federal lands, but it is the threat to communities and infrastructure downstream and downwind, including to military and commercial aviation, that drives the need to properly monitor volcanic activity and provide forecasts and notifications of expected hazards. Waiting until unrest escalates at a volcano then reacting to improve sparse monitoring arrays results in the loss of precious time and data as scientists, civil authorities, citizens, and businesses play "catch up" with a dangerous force of nature. NVEWS is a proposal to address monitoring needs at potentially dangerous volcanoes that have inadequate ground-based monitoring or none at all and to move beyond a reactive approach to mitigating volcanic risk. The most hazardous volcanoes would be properly monitored well in advance of the onset of activity, making it possible for scientists to improve the timeliness and accuracy of hazard forecasts and for citizens to take proper and timely action to reduce risk. The first step in developing NVEWS was a systematic assessment of (1) threats posed by U.S. volcanoes to human life and enterprise, (2) current monitoring capabilities at each volcano, and (3) improvements necessary to fill the worst monitoring gaps. The NVEWS assessment, published in 2005 ( http://pubs.usgs.gov/of/2005/1164/ ), shows that a few volcanoes are relatively well monitored with telemetered instrument arrays of various types. Many other volcanoes are monitored primarily by a network of sparsely distributed seismic instruments that lack the sensitivity to detect the subtle earthquakes that commonly characterize the earliest stages of unrest. Some hazardous volcanoes have no ground-based monitoring whatsoever. The overall result of the NVEWS assessment is the identification of 57 priority volcanoes that are undermonitored for the threats posed and thus targets for improved monitoring networks.

Fact Sheet↗

Lahars: Origins, behavior and hazards

Volcanic debris flows that originate at potentially active volcanoes are called lahars. Lahars are like debris flows in non-volcanic terrain but can most notably differ in origin and size. Primary lahars occur during eruptions and may have novel origins such as turbulent mixing of hot rock moving across ice- and snow-clad volcanoes and eruptions through crater lakes. Lahars range in volume to more than a cubic kilometer (10 9 m 3 ), with the biggest ones caused by huge deep-seated flank collapses of water-saturated edifice rock. Because they can be so voluminous, can have high water contents, and commonly can be clay rich, these lahars can travel tens to even hundreds of kilometers. Long transport causes evolution of flow types from flood flow to hyperconcentrated flow to debris flow. Lahars capable of traveling far downstream are commonly sufficiently liquefied that they drape valley slopes and leave behind thin deposits as they pass downstream. Only in valley bottoms are lahars likely to emplace thick deposits, and even there the deposits are apt to be much thinner than peak flow depths. Flows with long transport change character with time and distance downstream. Deposits, especially those in valley bottoms, can accrete during intervals that represent a significant proportion of the time it takes the flow to pass (typically minutes). The combination of flows changing character and their progressive accretion imposes distinctive characteristics on their deposits such as normal and inverse grading. Historically, lahars have caused thousands of fatalities and destroyed entire towns. Perhaps the most disastrous known lahar occurred in 1985 at Nevado del Ruiz in Colombia and killed more than 23,000 people. Since that disaster, an increasing awareness of lahar hazards has led to efforts to mitigate them. In recent decades, improved land-use decisions, monitoring and communication have improved hazard responses and saved many lives. Lahar hazard maps and development of lahar inundation models have helped planners and people at risk to better understand the nature of the risk owing to lahars.

Book chapter↗

Seismographs, sensors, and satellites: Better technology for safer communities

In the past 25 years, our ability to measure, monitor, and model the processes that lead to natural disasters has increased dramatically. Equally important has been the improvement in our technological capability to communicate information about hazards to those whose lives may be affected. These innovations in tracking and communicating the changes-floods, earthquakes, wildfires, volcanic eruptions-in our dynamic planet, supported by a deeper understanding of earth processes, enable us to expand our predictive capabilities and point the way to a safer future. ?? 2004 Elsevier Ltd. All rights reserved.

Technology in Society↗

The 3D Elevation Program—Supporting Montana’s economy

Introduction Montana, America’s fourth largest State with an area of 147,040 square miles, is defined by its diverse terrain. The western two-fifths of the State falls within the Rocky Mountains and the eastern three-fifths is in the Great Plains. Because of its location along the Continental Divide, the rivers in Montana drain into either the Pacific Ocean or the Gulf of Mexico. Montana is often called the Treasure State due to its mineral wealth, which includes oil, gas, and coal, but the State’s primary economic activity is agriculture. Other economic activities include natural resources conservation, water supply and quality, infrastructure and construction management, flood risk management, and geologic resource assessment and hazard mitigation. Critical applications that meet the State’s management needs depend on light detection and ranging (lidar) data that provide a highly detailed three-dimensional (3D) model of the Earth’s surface and aboveground features.

Montana↗

The 3D Elevation Program: summary for Pennsylvania

Elevation data are essential to a broad range of applications, including forest resources management, wildlife and habitat management, national security, recreation, and many others. For the Commonwealth of Pennsylvania, elevation data are critical for natural resources conservation (including the effects of drilling for oil and natural gas), agriculture and precision farming, flood risk management, infrastructure and construction management, water supply and quality, geologic resource assessment and hazard mitigation, and other business uses. Today, high-density light detection and ranging (lidar) data are the primary sources for deriving elevation models and other datasets. Federal, State, and local agencies work in partnership to replace data that are older and of lower quality. A joint goal of Commonwealth and Federal partners is to provide a temporal and density refresh of the current statewide coverage in order to support existing and emerging applications enabled by improved lidar data. The National Enhanced Elevation Assessment evaluated multiple elevation data acquisition options to determine the optimal data quality and data replacement cycle relative to cost to meet the identified requirements of the user community. The evaluation demonstrated that lidar acquisition at quality level 2 for the conterminous United States and quality level 5 interferometric synthetic aperture radar (ifsar) data for Alaska with a 6- to 10-year acquisition cycle provided the highest benefit/cost ratios. The 3D Elevation Program (3DEP) initiative selected an 8-year acquisition cycle for the respective quality levels. 3DEP, managed by the U.S. Geological Survey, the Office of Management and Budget Circular A–16 lead agency for terrestrial elevation data, responds to the growing need for high-quality topographic data and a wide range of other 3D representations of the Nation’s natural and constructed features.

Pennsylvania↗

Introduction to the special issue on “Understanding and predicting change in the coastal ecosystems of the northern Gulf of Mexico”

The coastal region of the northern Gulf of Mexico owes its current landscape structure to an array of tectonic, erosional and depositional, climatic, geochemical, hydrological, ecological, and human processes that have resulted in some of the world's most complex, dynamic, productive, and threatened ecosystems. Catastrophic hurricane landfalls, ongoing subsidence and erosion exacerbated by sea-level rise, disintegration of barrier island chains, and high rates of wetland loss have called attention to the vulnerability of northern Gulf coast ecosystems, habitats, built infrastructure, and economy to natural and anthropogenic threats. The devastating hurricanes of 2005 (Katrina and Rita) motivated the U.S. Geological Survey Coastal and Marine Geology Program and partnering researchers to pursue studies aimed at understanding and predicting landscape change and the associated storm hazard vulnerability of northern Gulf coast region ecosystems and human communities. Attaining this science goal requires increased knowledge of landscape evolution on geologic, historical, and human time scales, and analysis of the implications of such changes in the natural and built components of the landscape for hurricane impact susceptibility. This Special Issue of the Journal of Coastal Research communicates northern Gulf of Mexico research results that (1) improve knowledge of prior climates and depositional environments, (2) assess broad regional ecosystem structure and change over Holocene to human time scales, (3) undertake process studies and change analyses of dynamic landscape components, and (4) integrate framework, climate, variable time and spatial scale mapping, monitoring, and discipline-specific process investigations within interdisciplinary studies.

Journal of Coastal Research↗

Hydrocarbon potential, geologic hazards, and the technology, time-frame and infrastructure for exploration and development of the lower Cook Inlet, Alaska; a preliminary assessment

The Lower Cook Inlet Outer Continental Shelf (OCS) contains 5600 km 2 of submerged land in less than 200 m of water 150 to 350 km southwest of Anchorage, Alaska. This area could contain from 0.3 to 1.4 billion barrels of oil and from 0.6 to 2.7 trillion cubic feet of natural gas depending upon the statistical confidence level indicated. The known geology of this submerged area, is extrapolated to the offshore from onshore data. The sedimentary rocks are as old as Triassic and as young as Pleistocene. The Mesozoic strata include volcanic rocks, volcanoclastic and marine clastic sediments. Tertiary, rocks from which the oil and gas in Upper Cook Inlet are produced, consist of nonmarine conglomerate, sandstone, siltstone and coal. The potential objective section for oil and gas in this OCS area ranges from Middle Jurassic through the Tertiary. The present structural configuration of this area is a northeast trending trough filled with Tertiary sediments. The trough is flanked by two major faults, the Bruin Bay fault on the northwest and the Border Ranges fault on the southeast. Between these faults is the OCS area containing anticlinal structures and faults which may be traps for hydrocarbons. Potential geologic hazards are present in this area. It is an area of intense tectonism expressed as seismic activity (earthquakes) and volcanic eruptions which produce many natural disturbances including tsunamis. This distribution of soft sediment and other submarine features which relate to geologic hazards are only generally known.

Alaska↗

Communicating hazards—A social science review to meet U.S. Geological Survey needs

This report is for U.S. Geological Survey (USGS)—and any other—hazard scientists who want to improve the understanding and use of their scientific information, particularly by non-experts. In order for people to use science, they need to understand it. The highly technical, specialized nature of scientific information makes that difficult, particularly when few scientists are trained to communicate with people outside their fields. These issues are of special importance to the USGS because it has many users who are not scientists and because it develops and applies hazard science to help protect the safety, security, and economic well-being of our Nation. In 2010, the Science Application for Risk Reduction group at the USGS discovered the Center for Research on Environmental Decisions (CRED) guide, “The Psychology of Climate Change Communication.” Ever since, a growing number of USGS staff who need to communicate about hazards have used that guide and have asked CRED for a companion report dedicated to hazard communication to harness knowledge from more than 50 years of social science research. In 2016, the USGS and CRED launched a collaboration to develop that companion report. Ultimately, a CRED hazard communication guide would be a Columbia University publication with a wide focus and would include many hazards that are outside the USGS purview. This report is a first step and concentrates strictly on hazard communication needs at the USGS. To identify those needs and tailor this effort to USGS hazard communication priorities, this collaboration began with telephone interviews and an online survey of USGS staff. This report is the result; it summarizes social science research and experience in the areas of hazard communication that USGS participants deemed most important to include.

Circular↗