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USGS2023

Decision science as a framework for combining geomorphological and ecological modeling for the management of coastal systems

The loss of ecosystem services due to climate change and coastal development is projected to have significant impacts on local economies and conservation of natural resources. Consequently, there has been an increase in coastal management activities such as living shorelines, oyster reef restoration, marsh restoration, beach and dune nourishment, and revegetation projects. Coastal management decisions are complex and include challenging trade-offs. Decision science offers a useful framework to address such complex problems. Here, we provide a synthesis about how decision science can help to integrate research from multiple disciplines (physical and life sciences) with management of coastal and marine systems. Specifically, we discuss the importance of considering concepts and techniques from ecology, coastal geology, geomorphology, climate science, oceanography, and decision analysis when developing conservation plans for coastal restoration. We illustrate the process with several coastal restoration studies. Our capstone example is based on a recent barrier island restoration assessment project at Dauphin Island, Alabama, which included the development of geomorphological and ecological models. We show how decision science can be used as a framework to combine geomorphological and ecological modeling to help inform management decisions while considering uncertainty about system changes and risk tolerance. We also build on our examples through a review of recently developed techniques for spatial conservation planning for land acquisition decisions and the application of adaptive management for sequential decisions.

Alabama↗

USGS2018

Clarifying regional hydrologic controls of the Marañón River, Peru through rapid assessment to inform system-wide basin planning approaches

We use remote sensing to enhance the interpretation of the first baseline dataset of hydrologic, isotopic and hydrochemical variables spanning 620 km of the upper Marañón River, in Andean Peru, from the steep alpine canyons to the lower lying jungle. Remote, data-scarce river systems are under increased hydropower development pressure to meet rising energy demands. The upstream-downstream river continuum, which serves as a conduit for resource exchange across ecosystems, is at risk, potentially endangering the people, environments, and economies that rely on river resources. The Marañón River, one of the final free-flowing headwater connections between the Andes and the Amazon, is the subject of myriad large-scale hydropower proposals. Due to challenging access, environmental data are scarce in the upper Marañón, limiting our ability to do system-wide river basin planning. We capture key processes and transitions in the context of hydropower development. Two hydrologic regimes control the Marañón dry-season flow: in the higher-elevation upper reaches, a substantial baseflow is fed by groundwater recharged from wet season rains, in contrast to the lower reaches where the mainstem discharge is controlled by rain-fed tributaries that receive rain from lowland Amazon moisture systems. Sustainability of the upper corridor’s dry-season baseflow appears to be more highly connected to the massive natural storage capacity of extensive wetlands in the puna (alpine grasslands) than with cryospheric water inputs. The extent and conservation of puna ecosystems and glacier reservoirs may be interdependent, bringing to bear important conservation questions in the context of changing climate and land use in the region. More generally, this case study demonstrates an efficient combined remote sensing and field observation approach to address data scarcity across regional scales in mountain basins facing imminent rapid change.

Marañón River↗

USGS2011

Discussions of ODP Leg 205 and drilling of Middle America Seismogenic Zone

Erosional convergent margins, where material is removed from the base of the upper plate and subducted on the lower plate, are fundamental features of the Circum Pacific. The erosional Middle America Trench convergent Pacific margin, remarkable for its broad diversity of dynamic environments, is a natural laboratory for studying convergent margin processes and seismogenesis. These environments include a shallow and deep trench axis, shallow-to-steep-dipping plate interfaces, abnormally hot-to-cold subducting plate temperatures, and a subducting plate with smooth morphology bordering basement ridges and seamounts. The subducting topography accelerates erosion and localizes seismicity.

Middle America Trench, Pacific Ocean↗

USGS2022

Winter severity affects occupancy of spring- and summer-breeding anurans across the eastern United States

Aim Climate change is an increasingly important driver of biodiversity loss. The ectothermic nature of amphibians may make them particularly sensitive to changes in temperature and precipitation regimes, adding to declines from other threats. While active season environmental conditions can influence growth and survival, effects of variation in winter conditions on population dynamics are less well-studied. Given that extreme winter temperatures can influence amphibian survival and fitness, we expected that increased winter severity—as measured by variability in winter temperatures and snow cover—would be associated with decreased occupancy, and that populations that experience more severe winters would have the largest sensitivities and show the greatest declines. Location Eastern United States. Time period 2001–2015. Major taxa studied Anurans. Methods We used large-scale citizen science data from the eastern half of the United States, a diverse biogeographic and climatic region, to assess how variation in winter severity influenced occupancy dynamics (i.e. presence or absence of species across sites and years) of 11 spring and summer breeding anuran species. Results Most species had increased occupancy in years with greater than average snow cover and warmer than average mean winter temperatures. Surprisingly, climatic conditions in winter affected occupancy dynamics of species with varying life history characteristics, including both spring and summer breeding species, those that overwinter under the soil, and those that overwinter in ponds and stream beds. For two wide-ranging species ( Lithobates catesbeianus and Lithobates clamitans ), colder winter temperatures reduced occupancy more at northern latitudes, while the association between days of snow cover and latitude was equivocal. Main conclusions As the climate continues to change, expected reductions in snowpack may reduce occupancy of already declining anuran populations, while milder winters may improve overwinter survival for some species. The contradictory impacts of temperature and snow cover illustrate the importance of considering multi-dimensional impacts of climate change on anuran populations.

Diversity and Distributions↗

USGS2013

River flow changes related to land and water management practices across the conterminous United States

The effects of land and water management practices (LWMP)—such as the construction of dams and roads—on river flows typically have been studied at the scale of single river watersheds or for a single type of LWMP. For the most part, assessments of the relative effects of multiple LWMP within many river watersheds across regional and national scales have been lacking. This study assesses flow alteration—quantified as deviation of several flow metrics from natural conditions—at 4196 gauged rivers affected by a variety of LWMP across the conterminous United States. The most widespread causes of flow changes among the LWMP considered were road density and dams. Agricultural development and wastewater discharges also were associated with flow changes in some regions. Dams generally reduced most attributes of flow, whereas road density, agriculture and wastewater discharges tended to be associated with increased flows compared to their natural condition.

Science of the Total Environment↗

USGS2023

Integrated rangeland fire management strategy actionable science plan completion assessment—Fire topic, 2015–20

Loss and degradation of sagebrush rangelands due to an accelerated invasive annual grass-wildfire cycle and other stressors are significant management, conservation, and economic issues in the western United States. These sagebrush rangelands comprise a unique biome spanning 11 states, support over 350 wildlife species, and provide important ecosystem services that include stabilizing the economies of western communities. Impacts to sagebrush ecosystem processes over large areas due to the annual grass-wildfire cycle necessitated the development of a coordinated, science-based strategy for improving efforts to achieve long-term protection, conservation, and restoration of sagebrush rangelands, which was framed in 2015 under the Integrated Rangeland Fire Management Strategy (IRFMS). Central to this effort was the development of an Actionable Science Plan (Plan) that identified 37 priority science needs (Needs) for informing the actions proposed under the 5 topics (Fire, Invasives, Restoration, Sagebrush and Sage-Grouse, Climate and Weather) that were part of the collective focus of the IRFMS. Notable keys to this effort were identification of the Needs co-produced by managers and researchers, and a focus on resulting science being “actionable.” Substantial investments aimed at fulfilling the Needs identified in the Plan have been made since its release in 2016. While the state of the science has advanced considerably, the extent to which knowledge gaps remain relative to identified Needs is relatively unknown. Moreover, new Needs have likely emerged since the original strategy as results from actionable science reveal new questions and possible (yet untested) solutions. A quantifiable assessment of the progress made on the original science Needs can identify unresolved gaps and new information that can help inform prioritization of future research efforts. This report details a systematic literature review that evaluated how well peer-reviewed journal articles and formal technical reports published between January 1, 2015, and December 31, 2020, addressed eight needs (hereinafter known as “Needs”) identified under the Fire topic in the Plan, defined as any non-structure fire that occurs in vegetation or natural fuels, including wildfires and prescribed fires. The topic outlined research Needs broadly focused on understanding the mechanisms and management of threats posed to the maintenance of large, contiguous sagebrush rangelands by fire. We established the level of progress towards addressing each Need following a standardized set of criteria, and developed summaries detailing how research objectives nested within Needs identified in the Plan (‘Next Steps’) were either addressed well, partially addressed or remain outstanding (in other words., addressed poorly) in the literature through 2020. Our searches resulted in the inclusion of 156 science products that at least partially addressed a Need identified in the Fire topic. The Needs that were well and partially addressed included: studies of relationships between fire and the sagebrush ecosystem (Need 1) investigations of the responses of sage-grouse to burned area characteristics (Need 2); spatial modeling of fire risk (Need 3); studies of the effects of fuels management treatments (Need 4); sagebrush reduction treatments on multiple characteristics of the sagebrush ecosystem (Need 6); and assessments of the role of fire in maintaining healthy sagebrush communities (Need 7). Needs addressed poorly included: assessments of the effects of fuel breaks on sage-grouse (Need 5); and investigations of characteristics associated with the effectiveness of fuel breaks (Need 8). The information provided in this assessment will assist updating the Plan along with other science strategies.

western United States↗

USGS2015

Studies by the U.S. Geological Survey in Alaska, Volume 15

Summary Professional Paper 1814— Studies by the U.S. Geological Survey in Alaska, Volume 15 —continues a long-running series of collected volumes of U.S. Geological Survey (USGS) scientific reports on Alaska. This series presents new and sometimes preliminary findings that are of interest to Earth and biological scientists in academia, government, and industry; to land and resource managers; and to the general public. The series covers a broad spectrum of scientific topics, from various parts of Alaska, serving to emphasize the diversity of USGS efforts to meet the Nation’s needs for Earth-science information in the State. The USGS provides reliable scientific information to describe and understand the Earth; minimize loss of life and property from natural disasters; manage water, biological, energy, and mineral resources; and enhance and protect our quality of life.

Professional Paper↗

USGS2010

Assessment and management of ecological integrity: Chapter 12

Assessing and understanding the impacts of human activities on aquatic ecosystems has long been a focus of ecologists, water resources managers, and fisheries scientists. While traditional fisheries management focused on single-species approaches to enhance fish stocks, there is a growing emphasis on management approaches at community and ecosystem levels. Of course, as fisheries managers shift their attention from narrow (e.g., populations) to broad organizational scales (e.g., communities or ecosystems), ecological processes and management objectives become more complex. At the community level, fisheries managers may strive for a fish assemblage that is complex, persistent, and resilient to disturbance. Aquatic ecosystem level objectives may focus on management for habitat quality and ecological processes, such as nutrient dynamics, productivity, or trophic interactions, but a long-term goal of ecosystem management may be to maintain ecological integrity. However, human users and social, economic, and political demands of fisheries management often result in a reduction of ecological integrity in managed systems, and this conflict presents a principal challenge for the modern fisheries manager. The concepts of biotic integrity and ecological integrity are being applied in fisheries science, natural resource management, and environmental legislation, but explicit definitions of these terms are elusive. Biotic integrity of an ecosystem may be defined as the capability of supporting and maintaining an integrated, adaptive community of organisms having a species composition, diversity, and functional organization comparable to that of a natural habitat of the region (Karr and Dudley 1981). Following that, ecological integrity is the summation of chemical, physical, and biological integrity. Thus, the concept of ecological integrity extends beyond fish and represents a holistic approach for ecosystem management that is especially applicable to aquatic systems. The more general term, ecological condition, refers to the state of the physical, chemical, and biological characteristics of the environment and the processes and interactions that connect them. While the concept of ecological integrity may appear unambiguous, its assessment and practice are much less clear. Ecological integrity made its debut in the USA with the Clean Water Act (CWA) of 1972 (Federal Water Pollution Control Act, as amended through Public Law 107–303, November 27, 2002), which states only one objective, “to restore and maintain the chemical, physical, and biological integrity of the Nation’s waters.” This legislation compelled resource managers to focus on chemical pollution from point effluent sources, such as industrial and municipal outflows, as well as give attention to diffuse, chronic, and watershed effects on ecological integrity. Further, the CWA allowed pursuit of restoration programs in degraded water bodies and catalyzed the science and practice of restoration ecology. The term ecosystem health is often raised in discussions of ecological integrity. Perhaps it is natural to anthropomorphize our concern for personal health to ecosystems, so it becomes a useful metaphor for understanding the concept of ecological integrity. However, whether or not an ecosystem should be considered an entity, such as a superorganism, is a debate without end that began with early ecologists and continues today (Clements 1916; Suter 1993; Simon 1999a). Regardless, the ecosystem is indeed a natural unit with a level of organization and properties beyond the collection of those species that occupy it and presents the most appropriate spatial and organizational scale in which to assess and study ecological integrity. Streams and rivers serve as integrators of chemical, physical, and biological conditions across the landscape, and while the theory and practice associated with ecological integrity of aquatic systems is easily applied to flowing waters and is emphasized in this chapter, they are broadly applicable among all aquatic systems.

Book chapter↗

USGS2014

Summary of preliminary step-trend analysis from the Interagency Whitebark Pine Long-termMonitoring Program—2004-2013

In mixed and dominant stands, whitebark pine ( Pinus albicaulis ) occurs in over two million acres within the six national forests and two national parks that comprise the Greater Yellowstone Ecosystem (GYE). Currently, whitebark pine, an ecologically important species, is impacted by multiple ecological disturbances; white pine blister rust ( Cronartium ribicola ), mountain pine beetle ( Dendroctonus ponderosae ), wildfire, and climate change all pose significant threats to the persistence of whitebark pine populations. Substantial declines in whitebark pine populations have been documented throughout its range. Under the auspices of the Greater Yellowstone Coordinating Committee (GYCC), several agencies began a collaborative, long-term monitoring program to track and document the status of whitebark pine across the GYE. This alliance resulted in the formation of the Greater Yellowstone Whitebark Pine Monitoring Working Group (GYWPMWG), which consists of representatives from the U.S. Forest Service (USFS), National Park Service (NPS), U.S. Geological Survey (USGS), and Montana State University (MSU). This groundbased monitoring program was initiated in 2004 and follows a peer-reviewed protocol (GYWPMWG 2011). The program is led by the Greater Yellowstone Inventory and Monitoring Network (GRYN) of the National Park Service in coordination with multiple agencies. More information about this monitoring effort is available at: http://science. nature.nps.gov/im/units/gryn/monitor/whitebark_pine.cfm. The purpose of this report is to provide a draft summary of the first step-trend analysis for the interagency, long-term monitoring of whitebark pine health to the Interagency Grizzly Bear Study Team (IGBST) as part of a synthesis of the state of whitebark pine in the GYE. Due to the various stages of the analyses and reporting, this is the most efficient way to provide these results to the IGBST.

Natural Resource Data Series↗

USGS2002

Muskoxen

Muskoxen ( Ovibos moschatus ) disappeared from Alaska in the late 1800s, but returned to the Arctic National Wildlife Refuge when animals were reestablished into areas of former range in 1969-1970 (Klein 1988). Released at Barter Island (Kaktovik) and the Kavik River, muskoxen initially moved into regions that encompassed the 1002 Area on the coastal plain of the Arctic Refuge. From 1974 to 1986 the muskox population grew rapidly. By 1987, however, numbers declined in the regions that they had first occupied (Reynolds 1998 a ). Petroleum exploration and development could occur in muskox habitat in the 1002 Area of the Arctic Refuge. Status of the muskox population and factors related to trends in local abundance need to be determined if changes resulting from natural processes are to be separated from those that might result if industrial development is permitted in the Arctic Refuge. We developed a study with the following objectives to understand the dynamics of the muskox population in and near the 1002 Area of the Arctic Refuge: 1) determine abundance and rates of population increase, production, and survival; 2) document changes in population distribution over time, and 3) evaluate factors associated with changes in the number of muskoxen.

Alaska, Northwest Territories, Yukon Territory↗

USGS2011

USGS science for the Nation's changing coasts; shoreline change assessment

The coastline of the United States features some of the most popular tourist and recreational destinations in the world and is the site of intense residential, commercial, and industrial development. The coastal zone also has extensive and pristine natural areas, with diverse ecosystems providing essential habitat and resources that support wildlife, fish, and human use. Coastal erosion is a widespread process along most open-ocean shores of the United States that affects both developed and natural coastlines. As the coast changes, there are a wide range of ways that change can affect coastal communities, habitats, and the physical characteristics of the coast?including beach erosion, shoreline retreat, land loss, and damage to infrastructure. Global climate change will likely increase the rate of coastal change. A recent study of the U.S. Mid-Atlantic coast, for example, found that it is virtually certain that sandy beaches will erode faster in the future as sea level rises because of climate change. The U.S. Geological Survey (USGS) is responsible for conducting research on coastal change hazards, understanding the processes that cause coastal change, and developing models to predict future change. To understand and adapt to shoreline change, accurate information regarding the past and present configurations of the shoreline is essential. A comprehensive, nationally consistent analysis of shoreline movement is needed. To meet this national need, the USGS is conducting an analysis of historical shoreline changes along open-ocean coasts of the conterminous United States and parts of Alaska and Hawaii, as well as the coasts of the Great Lakes.

Fact Sheet↗

USGS2017

Building translational ecology communities of practice: insights from the field

Translational ecology (TE) prioritizes the understanding of social systems and decision contexts in order to address complex natural resource management issues. Although many practitioners in applied fields employ translational tactics, the body of literature addressing such approaches is limited. We present several case studies illustrating the principles of TE and the diversity of its applications. We anticipate that these examples will help others develop scientific products that decision makers can use “off the shelf” when solving critical ecological and social challenges. Our collective experience suggests that research of such immediate utility is rare. Long‐term commitment to working directly with partners to develop and reach shared goals is central to successful translation. The examples discussed here highlight the benefits of translational processes, including actionable scientific results, more informed policy making, increased investment in science‐driven solutions, and inspiration for partnerships. We aim to facilitate future TE‐based projects and build momentum for growing this community of practice.

Frontiers in Ecology and the Environment↗

USGS1987

A study of metal ion adsorption at low suspended-solid concentrations

A procedure for conducting adsorption studies at low suspended solid concentrations in natural waters (<50 mg l −1 ) is described. Methodological complications previously associated with such experiments have been overcome. Adsorption of zinc ion onto synthetic colloidal titania (TiO 2 ) was studied as a function of pH, supporting electrolyte (NaCl) concentration (0·1-0·002 m ) and particle concentration (2–50 mg l −1 ). The lack of success of the Davis Leckie site bonding model in describing Zn(II) adsorption emphasizes the need for further studies of adsorption at low suspended-solid concentrations.

Estuarine, Coastal and Shelf Science↗

USGS2014

Tracking change over time: River flooding

Landsat satellites have been capturing images of Earth from space since 1972. These images provide a long-term record of natural and human-induced changes on the global landscape. Comparing images from multiple years reveals slow and subtle changes as well as rapid and devastating ones. Landsat images are available from the Internet at no charge. Using the free software MultiSpec, students can track changes to the landscape over time—just like remote sensing scientists do! The objective of the Tracking Change Over Time lesson plan is to get students excited about studying the changing Earth. Intended for students in grades 5-8, the lesson plan is flexible and may be used as a student self-guided tutorial or as a teacher-led class lesson. Enhance students' learning of geography, map reading, earth science, and problem solving by seeing landscape changes from space. The objective of the Tracking Change Over Time lesson plan is to get students excited about studying the changing Earth. Intended for students in grades 5-8, the lesson plan is flexible and may be used as a student self-guided tutorial or as a teacher-led class lesson. Enhance students' learning of geography, map reading, earth science, and problem solving by seeing landscape changes from space.

Illinois, Indiana↗

USGS2016

Modeling the effects of land cover and use on landscape capability for urban ungulate populations

Expanding ungulate populations are causing concerns for wildlife professionals and residents in many urban areas worldwide. Nowhere is the phenomenon more apparent than in the eastern US, where urban white-tailed deer (Odocoileus virginianus) populations are increasing. Most habitat suitability models for deer have been developed in rural areas and across large (>1000 km2) spatial extents. Only recently have we begun to understand the factors that contribute to space use by deer over much smaller spatial extents. In this study, we explore the concepts, terminology, methodology and state-of-the-science in wildlife abundance modeling as applied to overabundant deer populations across heterogeneous urban landscapes. We used classified, high-resolution digital orthoimagery to extract landscape characteristics in several urban areas of upstate New York. In addition, we assessed deer abundance and distribution in 1-km2 blocks across each study area from either aerial surveys or ground-based distance sampling. We recorded the number of detections in each block and used binomial mixture models to explore important relationships between abundance and key landscape features. Finally, we cross-validated statistical models of abundance and compared covariate relationships across study sites. Study areas were characterized along a gradient of urbanization based on the proportions of impervious surfaces and natural vegetation which, based on the best-supported models, also distinguished blocks potentially occupied by deer. Models performed better at identifying occurrence of deer and worse at predicting abundance in cross-validation comparisons. We attribute poor predictive performance to differences in deer population trajectories over time. The proportion of impervious surfaces often yielded better predictions of abundance and occurrence than did the proportion of natural vegetation, which we attribute to a lack of certain land cover classes during cold and snowy winters. Merits and limitations of our approach to habitat suitability modeling are discussed in detail.

Book chapter↗

USGS2013

A spaceborne inventory of volcanic activity in Antarctica and southern oceans, 2000-10

Of the more than twenty historically active volcanoes in Antarctica and the sub-Antarctic region only two, to our knowledge, host any ground-based monitoring instruments. Moreover, because of their remoteness, most of the volcanoes are seldom visited, thus relegating the monitoring of volcanism in this region almost entirely to satellites. In this study, high temporal resolution satellite data from the Hawaii Institute of Geophysics and Planetology's MODVOLC system using MODIS (Moderate Resolution Imaging Spectroradiometer) are complemented with high spatial resolution data (ASTER, or Advanced Spaceborne Thermal Emission and Reflection Radiometer, and similar sensors) to document volcanic activity throughout the region during the period 2000–10. Five volcanoes were observed in eruption (Mount Erebus, Mount Belinda, Mount Michael, Heard Island and McDonald Island), which were predominantly low-level and effusive in nature. Mount Belinda produced tephra, building a cinder cone in addition to an extensive lava field. Five volcanoes exhibited detectable thermal, and presumed fumarolic, activity (Deception, Zavodovski, Candlemas, Bristol, and Bellingshausen islands). A minor eruption reported at Marion Island was not detected in our survey due to its small size. This study also discovered a new active vent on Mount Michael, tracked dramatic vent enlargement on Heard Island, and provides an improved picture of the morphology of some of the volcanoes.

Antarctic Science↗

USGS2011

Tracking change over time

Landsat satellites capture images of Earth from space-and have since 1972! These images provide a long-term record of natural and human-induced changes on the global landscape. Comparing images from multiple years reveals slow and subtle changes as well as rapid and devastating ones. Landsat images are available over the Internet at no charge. Using the free software MultiSpec, students can track changes to the landscape over time-just like remote sensing scientists do! The objective of the Tracking Change Over Time lesson plan is to get students excited about studying the changing Earth. Intended for students in grades 5-8, the lesson plan is flexible and may be used as a student self-guided tutorial or as a teacher-led class lesson. Enhance students' learning of geography, map reading, earth science, and problem solving by seeing landscape changes from space.

General Information Product↗

USGS2013

The stability of sulfate and hydrated sulfate minerals near ambient conditions and their significance in environmental and planetary sciences

Sulfate and hydrated sulfate minerals are abundant and ubiquitous on the surface of the Earth and also on other planets and their satellites. The humidity-buffer technique has been applied to study the stability of some of these minerals at 0.1 MPa in terms of temperature-relative humidity space on the basis of hydration-dehydration reversal experiments. Updated phase relations in the binary system MgSO 4 -H 2 O are presented, as an example, to show how reliable thermodynamic data for these minerals could be obtained based on these experimental results and thermodynamic principles. This approach has been applied to sulfate and hydrated sulfate minerals of other metals, including Fe (both ferrous and ferric), Zn, Ni, Co, Cd, and Cu. Metal-sulfate salts play important roles in the cycling of metals and sulfate in terrestrial systems, and the number of phases extends well beyond the simple sulfate salts that have thus far been investigated experimentally. The oxidation of sulfide minerals, particularly pyrite, is a common process that initiates the formation of efflorescent metal-sulfate minerals. Also, the overall abundance of iron-bearing sulfate salts in nature reflects the fact that the weathering of pyrite or pyrrhotite is the ultimate source for many of these phases. Many aspects of their environmental significance are reviewed, particularly in acute effects to aquatic ecosystems related to the dissolution of sulfate salts during rain storms or snow-melt events. Hydrous Mg, Ca, and Fe sulfates were identified on Mars, with wide distribution and very large quantities at many locations, on the basis of spectroscopic observations from orbital remote sensing and surface explorations by rovers. However, many of these findings do not reveal the detailed information on the degree of hydration that is essential for rigorous interpretation of the hydrologic history of Mars. Laboratory experiments on stability fields, reactions pathways, and reaction rates of hydrous sulfates likely to be found on Mars enhance our understanding of the degrees of hydration of various sulfates that should currently exist on Mars at various seasons and locations and during various atmospheric pressure and obliquity periods. Two sets of systematic experiments were described; one on hydrous Mg sulfates and the other on hydrous Fe 3+ sulfates. Also, their implications to Mars sulfates mineralogy were discussed.

Journal of Asian Earth Sciences↗