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MODIS phenology image service ArcMap toolbox

Seasonal change is important to consider when managing conservation areas at landscape scales. The study of such patterns throughout the year is referred to as phenology. Recurring life-cycle events that are initiated and driven by environmental factors include animal migration and plant flowering. Phenological events capture public attention, such as fall color change in deciduous forests, the first flowering in spring, and for those with allergies, the start of the pollen season. These events can affect our daily lives, provide clues to help understand and manage ecosystems, and provide evidence of how climate variability can affect the natural cycle of plants and animals. Phenological observations can be gathered at a range of scales, from plots smaller than an acre to landscapes of hundreds to thousands of acres. Linking these observations to diverse disciplines such as evolutionary biology or climate sciences can help further research in species and ecosystem responses to climate change scenarios at appropriate scales. A cooperative study between the National Park Service (NPS), the U.S. Geological Survey (USGS), and the National Aeronautics and Space Administration (NASA) has been exploring how satellite information can be used to summarize phenological patterns observed at the park or landscape scale and how those summaries can be presented to both park managers and visitors. This study specifically addressed seasonal changes in plants, including the onset of growth, photosynthesis in the spring, and the senescence of deciduous vegetation in the fall. The primary objective of the work is to demonstrate that seasonality even in protected areas changes considerably across years. A major challenge is to decouple natural variability from possible trends—directional change that can lead to a permanent and radically different ecosystem state. Trends can be either a gradual degradation of the landscape (often from external influences) or steady improvement (by implementing long-term conservation plans). In either case, it is important to first grasp the magnitude of natural variation so that it is not confused with actual trends. This work used existing and freely available remote sensing data, specifically the NASA-funded 250-meter (m) spatial resolution land-surface phenology product for North America. This product is calculated from an annual record of vegetation health observed by NASA’s Moderate Resolution Imaging Spectroradiometer (MODIS) instrument. The land-surface phenology product is, in essence, a method to summarize all the observations throughout a year into a few key, ecologically relevant “metrics”.

Open-File Report↗

Vulnerabilities of national parks in the American Midwest to climate and land use changes

Many national parks in the American Midwest are surrounded by agricultural or urban areas or are in highly fragmented or rapidly changing landscapes. An environmental stressor is a physical, chemical, or biological condition that affects the functioning or productivity of species or ecosystems. Climate change is just one of many stressors on park natural resources; others include urbanization, land use change, air and water pollution, and so on. Understanding and comparing the relative vulnerability of a suite of parks to projected climate and land use changes is important for region-wide planning. A vulnerability assessment of 60 units in the 13-state U.S. National Park Service Midwestern administrative region to climate and land use change used existing data from multiple sources. Assessment included three components: individual park exposure (5 metrics), sensitivity (5 metrics), and constraints to adaptive capacity (8 metrics) under 2 future climate scenarios. The three components were combined into an overall vulnerability score. Metrics were measures of existing or projected conditions within park boundaries, within 10-kilometer buffers surrounding parks, and within ecoregions that contain or intersect them. Data were normalized within the range of values for all assessed parks, resulting in high, medium, and low relative rankings for exposure, sensitivity, constraints to adaptive capacity, and overall vulnerability. Results are consistent with assessments regarding patterns and rates of climate change nationwide but provide greater detail and relative risk for Midwestern parks. Park overall relative vulnerability did not differ between climate scenarios. Rankings for exposure, sensitivity, and constraints to adaptive capacity varied geographically and indicate regional conservation planning opportunities. The most important stressors for the most vulnerable Midwestern parks are those related to sensitivity (intrinsic characteristics of the park) and constraints on adaptive capacity (characteristics of the surrounding landscape) rather than exposure to external forces, including climate change. Output will allow individual park managers to understand which metrics weigh most heavily in the overall vulnerability of their park and can be used for region-wide responses and resource allocation for adaptation efforts.

Arkansas, Illinois, Indiana, Iowa, Kansas, Michiga↗

Sea-floor geology in central Rhode Island Sound south of Sakonnet Point, Rhode Island

The U.S. Geological Survey (USGS) and the National Oceanic and Atmospheric Administration (NOAA) are working together to study the sea floor along the northeastern coast of the United States. NOAA collected multibeam-echosounder data during hydrographic survey H11995 in a 63-square-kilometer area in central Rhode Island Sound, south of Sakonnet Point, Rhode Island. The USGS collected sediment samples, bottom video, and still photographs from 27 stations in this study area to verify an interpretation of the bathymetric data. Collected data are used to map areas of scour depressions and erosional outliers, megaripples, boulders, and relatively undisturbed modern marine sediments. In general, much of the eastern part of the study area, a submerged segment of the Harbor Hill-Roanoke Point-Charlestown-Buzzards Bay moraine, is bouldery. Bottom photography shows boulders are generally encrusted with hydrozoans, algae, and anemone. Scour depressions, presumably formed by long-period storm waves, and erosional outliers of Holocene sediments dominate the western part of the study area and several large areas in the east. The scour depressions tend to have coarser grained sediment than intervening erosional outliers. The coarseness likely creates turbulence in the water over these areas, which prevents fine-grained sediment deposition. Several small areas of megaripples are visible in the bathymetry data in the west. Other sandy areas are typically rippled, with burrows, worm tubes, and starfish present.

Rhode Island↗

Climate scenarios for California

Possible future climate changes in California are investigated from a varied set of climate change model simulations. These simulations, conducted by three state-of-the-art global climate models, provide trajectories from three greenhouse gas (GHG) emission scenarios. These scenarios and the resulting climate simulations are not “predictions,” but rather are a limited sample from among the many plausible pathways that may affect California’s climate. Future GHG concentrations are uncertain because they depend on future social, political, and technological pathways, and thus the IPCC has produced four “families” of emission scenarios. To explore some of these uncertainties, emissions scenarios A2 (a medium-high emissions) and B1 (low emissions) were selected from the current IPCC Fourth climate assessment, which provides several recent model simulations driven by A2 and B1 emissions. The global climate model simulations addressed here were from PCM1, the Parallel Climate Model from the National Center for Atmospheric Research (NCAR) and U.S. Department of Energy (DOE) group, and CM2.1 from the National Oceanic and Atmospheric Administration (NOAA) Geophysical Fluids Dynamics Laboratory (GFDL). As part of the scenarios assessment, a statistical technique using properties of historical weather data was employed to correct model biases and “downscale” the global-model simulation of future climates to a finer level of detail, onto a grid of approximately 7 miles (12 kilometers), which is more suitable for impact studies at the scales needed by California decision makers. In current climate-change simulations, temperatures over California warm significantly during the twenty-first century, with temperature increases from approximately +3ºF (1.5ºC) in the lower emissions scenario (B1) within the less responsive model (PCM1) to +8ºF (4.5ºC) in the higher emissions scenario (A2) within the more responsive model (CM2.1). Three of the simulations (all except the low-emission scenario run of the low-response model) exhibit more warming in summer than in winter. In all of the simulations, most precipitation continues to occur in winter, with virtually all derived from North Pacific winter storms. Relatively little change in overall precipitation is projected. Climate warming has a profound influence in diminishing snow accumulations, because there is more rain and less snow, and earlier snowmelt. These snow losses increase as the warming increases, so that they are most severe under climate changes projected by the more sensitive model with the higher GHG emissions.

California↗

Integrating science and resource management in Tampa Bay, Florida

Tampa Bay is recognized internationally for its remarkable progress towards recovery since it was pronounced "dead" in the late 1970s. Due to significant efforts by local governments, industries and private citizens throughout the watershed, water clarity in Tampa Bay is now equal to what it was in 1950, when population in the watershed was less than one-quarter of what it is today. Seagrass extent has increased by more than 8,000 acres since the mid-1980s, and fish and wildlife populations are increasing. Central to this successful turn-around has been the Tampa Bay resource management community's long-term commitment to development and implementation of strong science-based management strategies. Research institutions and agencies, including Eckerd College, the Florida Wildlife Commission Fish and Wildlife Research Institute, Mote Marine Laboratory, National Oceanic and Atmospheric Administration, the Southwest Florida Water Management District, University of South Florida, U.S. Environmental Protection Agency, U.S. Geological Survey, local and State governments, and private companies contribute significantly to the scientific basis of our understanding of Tampa Bay's structure and ecological function. Resource management agencies, including the Tampa Bay Regional Planning Council's Agency on Bay Management, the Southwest Florida Water Management District's Surface Water Improvement and Management Program, and the Tampa Bay Estuary Program, depend upon this scientific basis to develop and implement regional adaptive management programs. The importance of integrating science with management has become fully recognized by scientists and managers throughout the region, State and Nation. Scientific studies conducted in Tampa Bay over the past 10–15 years are increasingly diverse and complex, and resource management programs reflect our increased knowledge of geology, hydrology and hydrodynamics, ecology and restoration techniques. However, a synthesis of this research and its integration into resource management has not been prepared for Tampa Bay since the mid-1980s. The need for an up-to-date synthesis of Tampa Bay science and management has resulted in the production of this document. The U.S. Geological Survey recently completed a 5-year Tampa Bay Integrated Science Study, and the Tampa Bay Estuary Program updated the Comprehensive Conservation and Management Plan for Tampa Bay in 2006. These efforts build upon results of the many research and management studies and programs summarized here.

Florida↗

Southeast Regional Assessment Project for the National Climate Change and Wildlife Science Center, U.S. Geological Survey

The Southeastern United States spans a broad range of physiographic settings and maintains exceptionally high levels of faunal diversity. Unfortunately, many of these ecosystems are increasingly under threat due to rapid human development, and management agencies are increasingly aware of the potential effects that climate change will have on these ecosystems. Natural resource managers and conservation planners can be effective at preserving ecosystems in the face of these stressors only if they can adapt current conservation efforts to increase the overall resilience of the system. Climate change, in particular, challenges many of the basic assumptions used by conservation planners and managers. Previous conservation planning efforts identified and prioritized areas for conservation based on the current environmental conditions, such as habitat quality, and assumed that conditions in conservation lands would be largely controlled by management actions (including no action). Climate change, however, will likely alter important system drivers (temperature, precipitation, and sea-level rise) and make it difficult, if not impossible, to maintain recent historic conditions in conservation lands into the future. Climate change will also influence the future conservation potential of non-conservation lands, further complicating conservation planning. Therefore, there is a need to develop and adapt effective conservation strategies to cope with the effects of climate and landscape change on future environmental conditions. Congress recognized this important issue and authorized the U.S. Geological Survey (USGS) National Climate Change and Wildlife Science Center (NCCWSC; http://nccw.usgs.gov/) in the Fiscal Year 2008. The NCCWSC will produce science that will help resource management agencies anticipate and adapt to climate change impacts to fish, wildlife, and their habitats. With the release of Secretarial Order 3289 on September 14, 2009, the mandate of the NCCWSC was expanded to address climate change-related impacts on all Department of the Interior (DOI) resources. The NCCWSC will establish a network of eight DOI Regional Climate Science Centers (RCSCs) that will work with a variety of partners to provide natural resource managers with tools and information that will help them anticipate and adapt conservation planning and design for projected climate change. The forecasting products produced by the RCSCs will aid fish, wildlife, and land managers in designing suitable adaptive management approaches for their programs. The DOI also is developing Landscape Conservation Cooperatives (LCCs) as science and conservation action partnerships at subregional scales. The USGS is working with the Southeast Region of the U.S. Fish and Wildlife Service (FWS) to develop science collaboration between the future Southeast RCSC and future LCCs. The NCCWSC Southeast Regional Assessment Project (SERAP) will begin to develop regional downscaled climate models, land cover change models, regional ecological models, regional watershed models, and other science tools. Models and data produced by SERAP will be used in a collaborative process between the USGS, the FWS (LCCs), State and federal partners, nongovernmental organizations, and academia to produce science at appropriate scales to answer resource management questions. The SERAP will produce an assessment of climate change, and impacts on land cover, ecosystems, and priority species in the region. The predictive tools developed by the SERAP project team will allow end users to better understand potential impacts of climate change and sea level rise on terrestrial and aquatic populations in the Southeastern United States. The SERAP capitalizes on the integration of five existing projects: (1) the Multi-State Conservation Grants Program project "Designing Sustainable Landscapes," (2) the USGS multidisciplinary Science Thrust project "Water Availability for Ecological Needs," (3) the USGS Southeast Pilot Project "Climate Change in the Southeastern U.S. and its Impacts on Bird Distributions and Habitats," (4) a sea-level rise impacts study envisioned jointly with the National Oceanic and Atmospheric Administration (NOAA), and (5) two USGS sea-level rise impact assessment projects that address inundation hazards and provide probabilistic forecasts of coastal geomorphic change. The SERAP will expand on these existing projects and include the following tasks, which were initiated in summer 2009: * Regionally downscaled probabilistic climate-change projections * Integrated coastal assessment * Integrated terrestrial assessment * Multi-resolution assessment of potential climate change effects on biological resources: aquatic and hydrologic dynamics * Optimal conservation strategies to cope with climate change The SERAP seeks to formally integrate these tasks to aid conservation planning and design so that ecosystem management decisions can be optimized for providing desirable outcomes across a range of species and environments. The following chapters detail SERAP's efforts in providing a suite of regional climate, watershed, and landscape-change analyses and develop the interdisciplinary framework required for the biological planning phases of adaptive management and strategic conservation. The planning phase will include the identification of conservation alternatives, development of predictive models and decision support tools, and development of a template to address similar challenges and goals in other regions. The project teams will explore and develop ways to link the various ecological models arising from each component. The SERAP project team also will work closely with members of the LCCs and other partnerships throughout the life of the project to ensure that the objectives of the project meet resources mangers needs in the Southeast.

Open-File Report↗

Regional water-level changes for the Cambrian-Ordovician aquifer in Iowa, 1975 to 1997

The Cambrian-Ordovician aquifer is one of the principal sources of ground water for industry and municipalities in Iowa. The 1998 Iowa Administrative Code Chapter 52.4(3) states that water levels in the Cambrian-Ordovician aquifer are not to decline more than 200 feet from the 1977 baseline. The potentiometric-surface map of the Cambrian-Ordovician aquifer, known locally as the Jordan aquifer, prepared by the Iowa Department of Natural Resources-Geological Survey Bureau and the U.S. Geological Survey in 1978 using water levels measured during the 1975 water year is considered the 1977 baseline. For this study, water levels measured during the 1997 water year were used to construct a potentiometric-surface map that was compared to the 1977 baseline to describe water-level changes. Since 1975, water levels have declined in two areas of central and eastern Iowa. The maximum measured water-level decline is 133 feet in Johnson County in eastern Iowa. The estimated maximum rate of decline is 6 feet per year in Johnson County. Results from a two-layer, ground-water flow model of the Cambrian-Ordovician aquifer constructed by the U.S. Geological Survey in 1990 were compared to selected measured 1997 water levels. The difference between the simulated water levels and the 1997 maximum measured water levels ranges from 0 to about 150 feet, but most differences are less than 25 feet. The comparison indicates that the model may help estimate future water levels in the Cambrian-Ordovician aquifer as an aid in managing the resource.

Iowa↗

Environmental quality and preservation; reefs, corals, and carbonate sands; guides to reef-ecosystem health and environment

Introduction In recent years, the health of the entire coral reef ecosystem that lines the outer shelf off the Florida Keys has declined markedly. In particular, loss of those coral species that are the building blocks of solid reef framework has significant negative implications for economic vitality of the region. What are the reasons for this decline? Is it due to natural change, or are human activities (recreational diving, ship groundings, farmland runoff, nutrient influx, air-borne contaminants, groundwater pollutants) a contributing factor and if so, to what extent? At risk of loss are biologic resources of the reefs, including habitats for endangered species in shoreline mangroves, productive marine and wetland nurseries, and economic fisheries. A healthy reef ecosystem builds a protective offshore barrier to catastrophic wave action and storm surges generated by tropical storms and hurricanes. In turn, a healthy reef protects the homes, marinas, and infrastructure on the Florida Keys that have been designed to capture a lucrative tourism industry. A healthy reef ecosystem also protects inland agricultural and livestock areas of South Florida whose produce and meat feed much of the United States and other parts of the world. In cooperation with the National Oceanic and Atmospheric Administration's (NOAA) National Marine Sanctuary Program, the U.S. Geological Survey (USGS) continues longterm investigations of factors that may affect Florida's reefs. One of the first steps in distinguishing between natural change and the effects of human activities, however, is to determine how coral reefs have responded to past environmental change, before the advent of man. By so doing, accurate scientific information becomes available for Marine Sanctuary management to understand natural change and thus to assess and regulate potential human impact better. The USGS studies described here evaluate the distribution (location) and historic vitality (thickness) of Holocene reefs in South Florida, relative to type of underlying bedrock morphology, and their varied natural response to rising sea level. These studies also assess movement and accumulation of sands, relative to direction of prevailing energy, and origin of the component sand grains. Geophysical data collected with highresolution sound-wave instruments that provide pictures of the sediment and bedrock are used to interpret sediment thickness. Reef thickness is determined by collecting limestone rock cores by drilling. Drill cores through reefs are used to identify the coral species that built them and to determine how reefs reacted to rising sea level. These data are supplemented by using isotope-dating techniques to derive the carbon-14 (C14) age of the corals and mangrove peat in the cores. Mangrove peat forms in very shallow water and at the shoreline but is found today buried beneath offshore reefs.

Open-File Report↗

Sea-Floor geology and character of Eastern Rhode Island Sound West of Gay Head, Massachusetts

Gridded multibeam bathymetry covers approximately 102 square kilometers of sea floor in eastern Rhode Island Sound west of Gay Head, Massachusetts. Although originally collected for charting purposes during National Oceanic and Atmospheric Administration hydrographic survey H11922, these acoustic data and the sea-floor stations subsequently occupied to verify them (1) show the composition and terrain of the seabed, (2) provide information on sediment transport and benthic habitat, and (3) are part of an expanding series of studies that provide a fundamental framework for research and management activities (for example, windfarms and fisheries) along the Massachusetts inner continental shelf. Most of the sea floor in the study area has an undulating to faintly rippled appearance and is composed of bioturbated muddy sand, reflecting processes associated with sediment sorting and reworking. Shallower areas are composed of rippled sand and, where small fields of megaripples are present, indicate sedimentary environments characterized by processes associated with coarse bedload transport. Boulders and gravel were found on the floors of scour depressions and on top of an isolated bathymetric high where erosion has removed the Holocene marine sediments and exposed the underlying relict lag deposits of Pleistocene drift. The numerous scour depressions, which formed during storm-driven events, result in the juxtaposition of sea-floor areas with contrasting sedimentary environments and distinct gravel, sand, and muddy sand textures. This textural heterogeneity in turn creates a complex patchwork of habitats. Our observations of local variations in community structure suggest that this small-scale textural heterogeneity adds dramatically to the sound-wide benthic biological diversity.

Eastern Rhode Island Sound;West Of Gay Head;Massac↗

Ecological context for the North Pacific Landscape Conservation Cooperative

The North Pacific Landscape Conservation Cooperative (NPLCC) encompasses the temperate coastal rainforest and extends from the coastal mountains to the near-shore from the Kenai Peninsula, Alaska to Bodega Bay, California. The area spans multiple agency, state, and international boundaries over more than 22 degrees of latitude, including a wide range of type and intensity of human land-use activities. Development of NPLCC goals and administrative structures will be facilitated by a shared ecological context for discussing this expansive, diverse, and complex landscape. In support of activities to organize the NPLCC, we provided conceptual models to describe the ecological structure of the NPLCC. Recognizing that the boundaries of LCCs were primarily based on Level 2 of the hierarchical ecoregional classification of Omernik (Comission for Environmental Cooperation 1997), we used nested Level 3 ecoregions to define subregions within the NPLCC. Rather than develop conceptual models for all nine constituent subregions, we opted to consider five groups: Puget-Georgia Basin Lowland and Willamette Valley, Alaska-British Columbia Coast, Alaska-British Columbia Mountains, Klamath-Olympic-Cascade Mountains, and Washington-Oregon-Northern California Coast. At the conclusion of the project, we felt that the close relationship between mountain and coastal areas support combining them to create three major subregions: Alaska-British Columbia coast and mountains, Washington-Oregon-Northern California coast and mountains, and the lowlands of the Georgia Basin and Willamette Valley. The following figures present the Omernik Level 3 ecoregions comprising the NPLCC; how the ecoregions were grouped to create conceptual models; and conceptual models for each group. The five models each consist of a table listing resources, stressors, potential climate change impacts; a landcover map; and a cartoon to summarize the table and evoke the landscape. A final figure summarizes resources, stressors, and climate change impacts that are common across the NPLCC.

Alaska;British Columbia;California;Oregon;Washingt↗

General characteristics and availability of Landsat 3 and heat capacity mapping mission thermal infrared data

Two satellite systems launched by the National Aeronautics and Space Administration (NASA) in 1978 carried sensors which operated in the thermal infrared (IR) region of the electromagnetic spectrum, The final IR radiation data provide spectral information about the physical properties of the Earth's surficial materials not duplicated in either the visible or reflective IR wavelength regions. Landsat 3, launched on March 5, 1978, contained a thermal sensor as part of the multispectral scanner (MSS) system. The sensor operated in the 10.4- to 12.6-?m (band 8) wavelength region and produced imagery with a ground resolution of approximately 235 m. Launched on April 26) 1978) the Heat Capacity Mapping Mission (HCMM) spacecraft carried a sensor, the heat capacity mapping radiometer (HCMR) which operated in the 10.5- to 12.5?m wavelength region and produced imagery with a ground resolution of approximately 600 m at nadir. The HCMM satellite acquired over 6,600 data passes of visible (0.55-1.1 ?m), as well as thermal IR data, over North America, Europe, and Australia. General characteristics and availability of Landsat 3 and HCMM thermal IR data are discussed. Landsat 3 reflected IR band 7 (0.55-1.1 ?m) and Landsat 3 band 8 thermal data acquired over the eastern and western United States are analyzed and compared with HCMM visible, thermal IR, thermal inertia, and day-night temperature difference imagery for geologic applications. Digitally processed and enhanced HCMM data (high-pass filters, diagonal derivatives, and band ratios), produced by the U.S. Geological Survey, Flagstaff) Ariz., are presented for geologic interpretation.

Open-File Report↗

The volcano letter: A weekly news leaflet of the Hawaiian Volcano Research Association

The Volcano Letter was an informal publication issued at irregular intervals by the Hawaiian Volcano Observatory (HVO) during the years 1925 to 1955. Individual issues contain information on volcanic activity, volcano research, and volcano monitoring in Hawaii. Information on volcanic activity at other locations is also occasionally included. The Volcano Letter was published by HVO through multiple changes in administration, including the Hawaiian Volcano Research Association (1925 to 1932), the U.S. Geological Survey (1932 to 1935), the Department of the Interior (1935 to 1938), and the University of Hawai‘i (1938 to 1955). Issues 1-262 were published weekly from January 1, 1925, to January 2, 1930, and consisted of a single page of text. Issues 263-384, also published weekly, from January 9, 1930, to May 5, 1932, were generally longer—four pages— and provided more detail on volcanic activity, including photographs, maps, and plots. Weekly issues 385-387, published May 12-26, 1932, were a single page of text due to budget reductions brought on by the Great Depression. Budget restrictions reduced the publishing frequency to monthly for issues 388-428, covering the period of June 1932 to October 1935; these issues were generally shorter, 1-2 pages, and sometimes featured figures. From November 1935 to July 1938, issues 429-461 remained monthly but increased in length (generally eight pages) and featured figures frequently. Issues 462-530, published over the period of August 1938 to December 1955, varied in length from 2-15 pages, but were published quarterly, rather than monthly. Six of the Volcano Letters are misnumbered: Jan. 21, 1926 number is 55 though it should 56 July 29, 1926 number is 82 though it should be 83 Feb. 16, 1928 number is 161 though it should be 164 May 31, 1928 number is 197 though it should be 179 Nov. 29, 1928 number is 204 though it should be 205

Hawaii↗

The volcano letter: A weekly news leaflet of the Hawaiian Volcano Research Association - 1925

The Volcano Letter was an informal publication issued at irregular intervals by the Hawaiian Volcano Observatory (HVO) during the years 1925 to 1955. Individual issues contain information on volcanic activity, volcano research, and volcano monitoring in Hawaii. Information on volcanic activity at other locations is also occasionally included. The Volcano Letter was published by HVO through multiple changes in administration, including the Hawaiian Volcano Research Association (1925 to 1932), the U.S. Geological Survey (1932 to 1935), the Department of the Interior (1935 to 1938), and the University of Hawai‘i (1938 to 1955). Issues 1-262 were published weekly from January 1, 1925, to January 2, 1930, and consisted of a single page of text. Issues 263-384, also published weekly, from January 9, 1930, to May 5, 1932, were generally longer—four pages— and provided more detail on volcanic activity, including photographs, maps, and plots. Weekly issues 385-387, published May 12-26, 1932, were a single page of text due to budget reductions brought on by the Great Depression. Budget restrictions reduced the publishing frequency to monthly for issues 388-428, covering the period of June 1932 to October 1935; these issues were generally shorter, 1-2 pages, and sometimes featured figures. From November 1935 to July 1938, issues 429-461 remained monthly but increased in length (generally eight pages) and featured figures frequently. Issues 462-530, published over the period of August 1938 to December 1955, varied in length from 2-15 pages, but were published quarterly, rather than monthly. Six of the Volcano Letters are misnumbered: Jan. 21, 1926 number is 55 though it should 56 July 29, 1926 number is 82 though it should be 83 Feb. 16, 1928 number is 161 though it should be 164 May 31, 1928 number is 197 though it should be 179 Nov. 29, 1928 number is 204 though it should be 205

Hawaii↗

The volcano letter: A weekly news leaflet of the Hawaiian Volcano Research Association - 1926

The Volcano Letter was an informal publication issued at irregular intervals by the Hawaiian Volcano Observatory (HVO) during the years 1925 to 1955. Individual issues contain information on volcanic activity, volcano research, and volcano monitoring in Hawaii. Information on volcanic activity at other locations is also occasionally included. The Volcano Letter was published by HVO through multiple changes in administration, including the Hawaiian Volcano Research Association (1925 to 1932), the U.S. Geological Survey (1932 to 1935), the Department of the Interior (1935 to 1938), and the University of Hawai‘i (1938 to 1955). Issues 1-262 were published weekly from January 1, 1925, to January 2, 1930, and consisted of a single page of text. Issues 263-384, also published weekly, from January 9, 1930, to May 5, 1932, were generally longer—four pages— and provided more detail on volcanic activity, including photographs, maps, and plots. Weekly issues 385-387, published May 12-26, 1932, were a single page of text due to budget reductions brought on by the Great Depression. Budget restrictions reduced the publishing frequency to monthly for issues 388-428, covering the period of June 1932 to October 1935; these issues were generally shorter, 1-2 pages, and sometimes featured figures. From November 1935 to July 1938, issues 429-461 remained monthly but increased in length (generally eight pages) and featured figures frequently. Issues 462-530, published over the period of August 1938 to December 1955, varied in length from 2-15 pages, but were published quarterly, rather than monthly. Six of the Volcano Letters are misnumbered: Jan. 21, 1926 number is 55 though it should 56 July 29, 1926 number is 82 though it should be 83 Feb. 16, 1928 number is 161 though it should be 164 May 31, 1928 number is 197 though it should be 179 Nov. 29, 1928 number is 204 though it should be 205

Hawaii↗

The volcano letter: A weekly news leaflet of the Hawaiian Volcano Research Association - 1927

The Volcano Letter was an informal publication issued at irregular intervals by the Hawaiian Volcano Observatory (HVO) during the years 1925 to 1955. Individual issues contain information on volcanic activity, volcano research, and volcano monitoring in Hawaii. Information on volcanic activity at other locations is also occasionally included. The Volcano Letter was published by HVO through multiple changes in administration, including the Hawaiian Volcano Research Association (1925 to 1932), the U.S. Geological Survey (1932 to 1935), the Department of the Interior (1935 to 1938), and the University of Hawai‘i (1938 to 1955). Issues 1-262 were published weekly from January 1, 1925, to January 2, 1930, and consisted of a single page of text. Issues 263-384, also published weekly, from January 9, 1930, to May 5, 1932, were generally longer—four pages— and provided more detail on volcanic activity, including photographs, maps, and plots. Weekly issues 385-387, published May 12-26, 1932, were a single page of text due to budget reductions brought on by the Great Depression. Budget restrictions reduced the publishing frequency to monthly for issues 388-428, covering the period of June 1932 to October 1935; these issues were generally shorter, 1-2 pages, and sometimes featured figures. From November 1935 to July 1938, issues 429-461 remained monthly but increased in length (generally eight pages) and featured figures frequently. Issues 462-530, published over the period of August 1938 to December 1955, varied in length from 2-15 pages, but were published quarterly, rather than monthly. Six of the Volcano Letters are misnumbered: Jan. 21, 1926 number is 55 though it should 56 July 29, 1926 number is 82 though it should be 83 Feb. 16, 1928 number is 161 though it should be 164 May 31, 1928 number is 197 though it should be 179 Nov. 29, 1928 number is 204 though it should be 205

Hawaii↗

The volcano letter: A weekly news leaflet of the Hawaiian Volcano Research Association - 1928

The Volcano Letter was an informal publication issued at irregular intervals by the Hawaiian Volcano Observatory (HVO) during the years 1925 to 1955. Individual issues contain information on volcanic activity, volcano research, and volcano monitoring in Hawaii. Information on volcanic activity at other locations is also occasionally included. The Volcano Letter was published by HVO through multiple changes in administration, including the Hawaiian Volcano Research Association (1925 to 1932), the U.S. Geological Survey (1932 to 1935), the Department of the Interior (1935 to 1938), and the University of Hawai‘i (1938 to 1955). Issues 1-262 were published weekly from January 1, 1925, to January 2, 1930, and consisted of a single page of text. Issues 263-384, also published weekly, from January 9, 1930, to May 5, 1932, were generally longer—four pages— and provided more detail on volcanic activity, including photographs, maps, and plots. Weekly issues 385-387, published May 12-26, 1932, were a single page of text due to budget reductions brought on by the Great Depression. Budget restrictions reduced the publishing frequency to monthly for issues 388-428, covering the period of June 1932 to October 1935; these issues were generally shorter, 1-2 pages, and sometimes featured figures. From November 1935 to July 1938, issues 429-461 remained monthly but increased in length (generally eight pages) and featured figures frequently. Issues 462-530, published over the period of August 1938 to December 1955, varied in length from 2-15 pages, but were published quarterly, rather than monthly. Six of the Volcano Letters are misnumbered: Jan. 21, 1926 number is 55 though it should 56 July 29, 1926 number is 82 though it should be 83 Feb. 16, 1928 number is 161 though it should be 164 May 31, 1928 number is 197 though it should be 179 Nov. 29, 1928 number is 204 though it should be 205

Hawaii↗

The volcano letter: A weekly news leaflet of the Hawaiian Volcano Research Association - 1929

The Volcano Letter was an informal publication issued at irregular intervals by the Hawaiian Volcano Observatory (HVO) during the years 1925 to 1955. Individual issues contain information on volcanic activity, volcano research, and volcano monitoring in Hawaii. Information on volcanic activity at other locations is also occasionally included. The Volcano Letter was published by HVO through multiple changes in administration, including the Hawaiian Volcano Research Association (1925 to 1932), the U.S. Geological Survey (1932 to 1935), the Department of the Interior (1935 to 1938), and the University of Hawai‘i (1938 to 1955). Issues 1-262 were published weekly from January 1, 1925, to January 2, 1930, and consisted of a single page of text. Issues 263-384, also published weekly, from January 9, 1930, to May 5, 1932, were generally longer—four pages— and provided more detail on volcanic activity, including photographs, maps, and plots. Weekly issues 385-387, published May 12-26, 1932, were a single page of text due to budget reductions brought on by the Great Depression. Budget restrictions reduced the publishing frequency to monthly for issues 388-428, covering the period of June 1932 to October 1935; these issues were generally shorter, 1-2 pages, and sometimes featured figures. From November 1935 to July 1938, issues 429-461 remained monthly but increased in length (generally eight pages) and featured figures frequently. Issues 462-530, published over the period of August 1938 to December 1955, varied in length from 2-15 pages, but were published quarterly, rather than monthly. Six of the Volcano Letters are misnumbered: Jan. 21, 1926 number is 55 though it should 56 July 29, 1926 number is 82 though it should be 83 Feb. 16, 1928 number is 161 though it should be 164 May 31, 1928 number is 197 though it should be 179 Nov. 29, 1928 number is 204 though it should be 205

Hawaii↗

The volcano letter: A weekly news leaflet of the Hawaiian Volcano Research Association - 1930

The Volcano Letter was an informal publication issued at irregular intervals by the Hawaiian Volcano Observatory (HVO) during the years 1925 to 1955. Individual issues contain information on volcanic activity, volcano research, and volcano monitoring in Hawaii. Information on volcanic activity at other locations is also occasionally included. The Volcano Letter was published by HVO through multiple changes in administration, including the Hawaiian Volcano Research Association (1925 to 1932), the U.S. Geological Survey (1932 to 1935), the Department of the Interior (1935 to 1938), and the University of Hawai‘i (1938 to 1955). Issues 1-262 were published weekly from January 1, 1925, to January 2, 1930, and consisted of a single page of text. Issues 263-384, also published weekly, from January 9, 1930, to May 5, 1932, were generally longer—four pages— and provided more detail on volcanic activity, including photographs, maps, and plots. Weekly issues 385-387, published May 12-26, 1932, were a single page of text due to budget reductions brought on by the Great Depression. Budget restrictions reduced the publishing frequency to monthly for issues 388-428, covering the period of June 1932 to October 1935; these issues were generally shorter, 1-2 pages, and sometimes featured figures. From November 1935 to July 1938, issues 429-461 remained monthly but increased in length (generally eight pages) and featured figures frequently. Issues 462-530, published over the period of August 1938 to December 1955, varied in length from 2-15 pages, but were published quarterly, rather than monthly. Six of the Volcano Letters are misnumbered: Jan. 21, 1926 number is 55 though it should 56 July 29, 1926 number is 82 though it should be 83 Feb. 16, 1928 number is 161 though it should be 164 May 31, 1928 number is 197 though it should be 179 Nov. 29, 1928 number is 204 though it should be 205

Hawaii↗