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2012

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Articles 601 - 630 of 988

Full-Text Articles in Earth Sciences

The Giant Cretaceous Coelacanth (Actinistia, Sarcopterygii) Megalocoelacanthus Dobiei Schwimmer, Stewart & Williams, 1994, And Its Bearing On Latimerioidei Interrelationships, David R. Schwimmer Jan 2012

The Giant Cretaceous Coelacanth (Actinistia, Sarcopterygii) Megalocoelacanthus Dobiei Schwimmer, Stewart & Williams, 1994, And Its Bearing On Latimerioidei Interrelationships, David R. Schwimmer

Faculty Bibliography

We present a redescription of Megalocoelacanthus dobiei, a giant fossil coelacanth from Upper Cretaceous strata of North America. Megalocoelacanthus has been previously described on the basis of composite material that consisted of isolated elements. Consequently, many aspects of its anatomy have remained unknown as well as its phylogenetic relationships with other coelacanths. Previous studies have suggested that Megalocoelacanthus is closer to Latimeria and Macropoma than to Mawsonia. However, this assumption was based only on the overall similarity of few anatomical features, rather than on a phylogenetic character analysis. A new, and outstandingly preserved specimen from the Niobrara Formation in Kansas …


Overview Of The Strategic And Structural Evolution Of The Talladega Slate Belt, Alabama Appalachians, Clinton Barineau Jan 2012

Overview Of The Strategic And Structural Evolution Of The Talladega Slate Belt, Alabama Appalachians, Clinton Barineau

Faculty Bibliography

The allochthonous Talladega belt of eastern-northeastern Alabama and northwestern Georgia is a northeast striking, fault bounded block of lower greenschist facies metasedimentary and metaigneous rocks that formed along the margin of Laurentia at or outboard of the seaward edge of the Alabama promontory. Bounded by metamorphic rocks of the higher grade Neoproterozoic(?) to Carboniferous eastern Blue Ridge on the southeast and unmetamorphosed to anchimetamorphic Paleozoic rocks of the Appalachian foreland on the northwest, the Talladega belt includes shelf facies rocks of the latest Neoproterozoic/earliest Cambrian Kahatchee Mountain Group, Cambrian-Ordovician Sylacauga Marble Group, and the latest Silurian(?) to uppermost Devonian/earliest Mississippian …


Paleobiology And Geochemistry Of Siliceous Concretions With Trilobites And Brooksella, David R. Schwimmer Jan 2012

Paleobiology And Geochemistry Of Siliceous Concretions With Trilobites And Brooksella, David R. Schwimmer

Faculty Bibliography

No abstract provided.


Strain Analysis On The Sub-Lay Dam Unconformity Near Jumbo, Alabama, Clinton Barineau Jan 2012

Strain Analysis On The Sub-Lay Dam Unconformity Near Jumbo, Alabama, Clinton Barineau

Faculty Bibliography

No abstract provided.


The Talladega And Ashland-Wedowee-Emuckfaw Belts Of Alabama: Geological Overview, Clinton Barineau Jan 2012

The Talladega And Ashland-Wedowee-Emuckfaw Belts Of Alabama: Geological Overview, Clinton Barineau

Faculty Bibliography

No abstract provided.


Modeling Regional Radicarbon Trends: A Case Study From The East Texas Woodland Period, Robert Z. Selden Jr. Jan 2012

Modeling Regional Radicarbon Trends: A Case Study From The East Texas Woodland Period, Robert Z. Selden Jr.

CRHR: Archaeology

The East Texas Radiocarbon Database contributes to an analysis of tempo and place for Woodland era (~500 BC–AD 800) archaeological sites within the region. The temporal and spatial distributions of calibrated 14C ages (n = 127) with a standard deviation (ΔT) of 61 from archaeological sites with Woodland components (n = 51) are useful in exploring the development and geographical continuity of the peoples in east Texas, and lead to a refinement of our current chronological understanding of the period. While analysis of summed probability distributions (SPDs) produces less than significant findings due to sample size, they are used …


Fragilariopsis Diatom Evolution In Pliocene And Pleistocene Antarctic Shelf Sediments, Charlotte Sjunneskog, Christina R. Riesselman, Diane Winter, Reed Scherer Jan 2012

Fragilariopsis Diatom Evolution In Pliocene And Pleistocene Antarctic Shelf Sediments, Charlotte Sjunneskog, Christina R. Riesselman, Diane Winter, Reed Scherer

ANDRILL Research and Publications

The late Pliocene – early Pleistocene sediment record in the AND-1B core from the McMurdo Sound, Ross Sea, Antarctica, displays a rich diversity and high abundance of diatoms, including several new morphologies within the genus Fragilariopsis. These new morphologies exhibit similarities to the extinct late Miocene/early Pliocene species Fragilariopsis aurica Gersonde and Fragilariopsis praecurta Gersonde, as well as to the modern sea ice-associated species Fragilariopsis ritscheri Hustedt and Fragilariopsis obliquecostata van Heurck. From the diverse morphologies present, we use light microscopy and scanning electron microscopy to identify and describe the characteristics of three new taxa, Fragilariopsis laqueata Riesselman, Fragilariopsis …


Groundwater Quality And Its Health Impact: An Assessment Of Dental Fluorosis In Rural Inhabitants Of The Main Ethiopian Rift, Tewodros Rango, Julia Kravchenko, Behailu Atlaw, Peter G. Mccornick, Marc Jeuland, Brittany Merola, Avner Vengosh Jan 2012

Groundwater Quality And Its Health Impact: An Assessment Of Dental Fluorosis In Rural Inhabitants Of The Main Ethiopian Rift, Tewodros Rango, Julia Kravchenko, Behailu Atlaw, Peter G. Mccornick, Marc Jeuland, Brittany Merola, Avner Vengosh

Daugherty Water for Food Global Institute: Faculty Publications

This study aims to assess the link between fluoride content in groundwater and its impact on dental health in rural communities of the Ethiopian Rift. A total of 148 water samples were collected from two drainage basins within the Main Ethiopian Rift (MER). In the Ziway-Shala basin in particular, wells had high fluoride levels (mean: 9.4 ± 10.5 mg/L; range: 1.1 to 68 mg/L), with 48 of 50 exceeding the WHO drinking water guideline limit of 1.5 mg/L. Total average daily intake of fluoride from drinking groundwater (calculated per weight unit) was also found to be six times higher than …


Relações Entre As Doenças Respiratórias E A Poluição Atmosférica E Variáveis Climáticas Na Cidade De Curitiba, Paraná, Brasil, Paulo R.B. Guimarães, Ricardo Berger, Fernando Lucambio Perez, Paulo Dt Dl Pires Jan 2012

Relações Entre As Doenças Respiratórias E A Poluição Atmosférica E Variáveis Climáticas Na Cidade De Curitiba, Paraná, Brasil, Paulo R.B. Guimarães, Ricardo Berger, Fernando Lucambio Perez, Paulo Dt Dl Pires

Daugherty Water for Food Global Institute: Faculty Publications

Neste estudo, foram observados níveis de concentrações de poluentes atmosféricos da cidade de Curitiba, no período de novembro de 2003 a junho de 2008, da estação automática de monitoramento da praça Ouvidor Pardinho. O objetivo foi desenvolver uma metodologia de modelagem estatística que explique o número de notificações de doenças respiratórias registradas em idosos (acima de 60 anos) e crianças (abaixo de 5 anos). Além das concentrações de poluentes, algumas variáveis climáticas foram analisadas. Após estudo de diversas metodologias estatísticas, considerou-se mais adequado o ajuste de Modelos Aditivos Generalizados para Locação, Escala e Forma. Os modelos ajustados apresentaram resultados satisfatórios …


As Unidades De Conservação E A Floresta Ombrófila Mista No Estado Do Paraná, Paulo Dt Dl Pires, Douglas Magnus Zeni Jr, Debora Gaulke Jan 2012

As Unidades De Conservação E A Floresta Ombrófila Mista No Estado Do Paraná, Paulo Dt Dl Pires, Douglas Magnus Zeni Jr, Debora Gaulke

Daugherty Water for Food Global Institute: Faculty Publications

O intenso processo de ocupação territorial, uso desordenado dos recursos naturais e destruição de áreas verdes iniciadas no século XIX, são os principais motivos da intensa devastação das Florestas com Araucárias. Como meio de efetivação da proteção e desenvolvimento florestal, o Brasil adotou em sua política ambiental a criação do Sistema de Unidades de Conservação nas categorias, de proteção integral e uso sustentável. Uma alternativa viável é a regulação dos estoques de madeira no Estado por meio de Unidade de Conservação de Uso Sustentável. O que se pretende a partir deste ponto é analisar a possibilidade da criação de regulamentação …


An Aphelaspis Zone (Upper Cambrian, Paibian) Trilobite Faunule In The Central Conasauga River Valley, North Georgia, Usa, David R. Schwimmer Jan 2012

An Aphelaspis Zone (Upper Cambrian, Paibian) Trilobite Faunule In The Central Conasauga River Valley, North Georgia, Usa, David R. Schwimmer

Faculty Bibliography

Middle and Upper Cambrian strata (Cambrian Series 3 and Furongian) in the southernmost Appalachians (Tennessee to Alabama) comprise the Conasauga Formation or Group. Heretofore, the youngest reported Conasauga beds in the Valley and Ridge Province of Georgia were of the late Middle Cambrian (Series 3: Drumian) Bolaspidella Zone, located on the western state boundary in the valley of the Coosa River. Two new localities sited eastward in the Conasauga River Valley, yield a diagnostic suite of trilobites from the Upper Cambrian Aphelaspis Zone. Very abundant, polymeroid trilobites at the primary locality are referable to Aphelaspis brachyphasis, which is a species …


Characteristics, Extent, And Tectonic Significance Of A Middle Ordovician Back-Arc Basin In The Southern Appalachian Blue Ridge, Clinton Barineau Jan 2012

Characteristics, Extent, And Tectonic Significance Of A Middle Ordovician Back-Arc Basin In The Southern Appalachian Blue Ridge, Clinton Barineau

Faculty Bibliography

A growing body of evidence suggests that a number of Ordovician-aged stratigraphic units in separate lithotectonic belts of the southern Appalachian orogen are genetically related, having formed in a back-arc setting on the Laurentian plate. Research on the Hillabee Greenstone in the Talladega belt and Pumpkinvinve Creek Formation and related bimodal metavolcanic rocks in the Dahlonega Gold belt suggest a similar temporal, spatial, and tectonic origin. Additionally, recent Ordovician isotopic ages for detrital zircons from the Wedowee and Emuckfaw Groups in the Ashland-WedoweeEmuckfaw belt of Alabama (eastern Blue Ridge), as well as stratigraphic correlations of these units with metasedimentary and …


Suitability Of Low Cost Commercial Off-The-Shelf Aerial Platforms And Consumer Grade Digital Cameras For Small Format Aerial Photography, Anthony Allen Turley Jan 2012

Suitability Of Low Cost Commercial Off-The-Shelf Aerial Platforms And Consumer Grade Digital Cameras For Small Format Aerial Photography, Anthony Allen Turley

Theses, Dissertations and Capstones

Many research projects require the use of aerial images. Wetlands evaluation, crop monitoring, wildfire management, environmental change detection, and forest inventory are but a few of the applications of aerial imagery. Low altitude Small Format Aerial Photography (SFAP) is a bridge between satellite and man-carrying aircraft image acquisition and ground-based photography. The author’s project evaluates digital images acquired using low cost commercial digital cameras and standard model airplanes to determine their suitability for remote sensing applications. Images from two different sites were obtained. Several photo missions were flown over each site, acquiring images in the visible and near infrared electromagnetic …


The Role Of Fine-Scale Habitat Associations In Structuring Spider Assemblages: Determinants Of Spatial Patterns In Community Compostion, Stephanie M. Cobbold Jan 2012

The Role Of Fine-Scale Habitat Associations In Structuring Spider Assemblages: Determinants Of Spatial Patterns In Community Compostion, Stephanie M. Cobbold

Green Canyon Environmental Research Area, Logan Utah

No abstract provided.


Livestock Foraging Behavior In Response To Sequence And Interactions Among Alkaloids, Tannins, And Saponins, Tiffany L. Jensen Jan 2012

Livestock Foraging Behavior In Response To Sequence And Interactions Among Alkaloids, Tannins, And Saponins, Tiffany L. Jensen

Green Canyon Environmental Research Area, Logan Utah

No abstract provided.


Delineating The 2007 Corn Belt Region, Chris Laingen Jan 2012

Delineating The 2007 Corn Belt Region, Chris Laingen

Faculty Research and Creative Activity

No abstract provided.


Strategies For Wildlife Disease Surveillance, Jonathan M. Sleeman, Christopher J. Brand, Scott D. Wright Jan 2012

Strategies For Wildlife Disease Surveillance, Jonathan M. Sleeman, Christopher J. Brand, Scott D. Wright

United States Geological Survey: Staff Publications

Epidemiologic surveillance is defined by the Centers for Disease Control and Prevention (CDC) as the "ongoing systematic and continuous collection, analysis, and interpretation of health data': The objective of surveillance is to generate data for rapid response to the detection of a disease of concern to apply prevention, control, or eradication measures as well as to evaluate such interventions. This is distinct from disease monitoring, which usually does not involve a particular response to disease detection.

Surveillance for wildlife diseases has increased in importance due to the emergence and re-emergence of wildlife diseases that are threats to human, animal, and …


Modeling Erosion And Sediment Delivery On Mountain Roads In Upper Deep Creek, Rebecca Louise Franklin Jan 2012

Modeling Erosion And Sediment Delivery On Mountain Roads In Upper Deep Creek, Rebecca Louise Franklin

Theses Digitization Project

Upper Deep Creek is a 250-square mile sub-watershed that is located in a mountainous, forested region of the San Bernardino National Forest in San Bernardino county in Southern California. It is widely acknowledged that in mountainous, forested watersheds, roads are a primary source of excess sediment that can enter stream networks and cause environmental degradation. The goal of this project was to screen the Upper Deep Creek road network using two erosion prediction models, the Washington Road Surface Erosion Model (WARSEM) and the Watershed Erosion Prediction Project (WEPP:Road), in order to identify road segments that are contributing significant amounts of …


P-T Conditions Of Selected Samples Across The Blue Ridge Province, Breana A. Felix Jan 2012

P-T Conditions Of Selected Samples Across The Blue Ridge Province, Breana A. Felix

Theses, Dissertations and Capstones

The Blue Ridge province of the Appalachian Mountains has a complex geologic history characterized by more than one metamorphic and deformational event. Mapping of the Blue Ridge has allowed for the province to be broken into the “sub” provinces western, central, and eastern Blue Ridge. The boundaries for these, however, are not well understood due to the difficulty in determining which orogenies caused each metamorphic event.

Detailed petrographic and microprobe analyses were carried out on 17 and 10 samples respectively. Outcrops from Ducktown and Marble in the western Blue Ridge (WBR), Savannah Church, Sylva, and Little Pine Garnet Mine in …


Depositional Environments And Sequence Stratigraphy Of A Breathitt Group Exposure, U.S. 25e, Flat Lick, Kentucky, Kathryn E. Hoffmeister, Eric G. Hogan, Steven M. Holland Jan 2012

Depositional Environments And Sequence Stratigraphy Of A Breathitt Group Exposure, U.S. 25e, Flat Lick, Kentucky, Kathryn E. Hoffmeister, Eric G. Hogan, Steven M. Holland

Information Circular--KGS

The Pennsylvanian fluvial deltaic Breathitt Group is exposed along U.S. 25E near Flat Lick, Ky. This exposure is ideal for field trips because of the quality of the exposure, its accessibility, the range of facies present, and its potential for demonstrating principles of outcrop-based sequence-stratigraphic interpretation. Eight facies are present and represent deposition in fluvial, delta-plain, and delta-front environments. Several facies contain an abundance of trace fossils, and a wide range of sedimentary structures are also present. Flooding surfaces are well developed in the delta front and delta plain and are characterized by abrupt contacts with distal, deeper-water deltaic environments …


Mapping Lava Flows From Nyamuragira Volcano (1967-2011) With Satellite Data And Automated Classification Methods, Elisabet Head, Ann L. Maclean, Simon A. Carn Jan 2012

Mapping Lava Flows From Nyamuragira Volcano (1967-2011) With Satellite Data And Automated Classification Methods, Elisabet Head, Ann L. Maclean, Simon A. Carn

Faculty Research and Creative Activity

The volume, location and extent of historical lava flows are important when assessing volcanic hazards, as well as the productivity or longevity of a volcanic system. We use a Landsat/Hyperion/ALI dataset and automated classification methods to map lava flows at Nyamuragira volcano (1967-2011) in the Democratic Republic of the Congo. The humid tropical climate ofNyamuragira is advantageous because its lava flows are emplaced onto heavily forested flanks, resulting in strong contrast between lava and vegetation, which contributes to efficient flow mapping. With increasing age, there is an increase in Landsat band-4 reflectance, suggesting lava flow revegetation with time. This results …


Silurian Graptolite, Conodont And Cryptospore Biostratigraphy Of The Gülüç Section In Ereğli, Zonguldak Terrane, Nw Anatolia, Turkey, Valeri Sachanski, Mehmet Cemal Göncüoğlu, Iskra Lakova, Ilina Boncheva, Gülnur Saydam-Demi̇ray Jan 2012

Silurian Graptolite, Conodont And Cryptospore Biostratigraphy Of The Gülüç Section In Ereğli, Zonguldak Terrane, Nw Anatolia, Turkey, Valeri Sachanski, Mehmet Cemal Göncüoğlu, Iskra Lakova, Ilina Boncheva, Gülnur Saydam-Demi̇ray

Turkish Journal of Earth Sciences

The studied Gülüç section of the Silurian Fındıklı Formation is situated on the western bank of Gülüç Creek in Ereğli, NW Anatolia, Turkey, in the eastern part of the Zonguldak Terrane. The Gülüç section consists of 3 sedimentary packages: greenish grey limy siltstones, 5-7 m thick (1), overlain by an irregular alternation of black shales and clayey limestones, about 15 m thick (2), and a 6-7 m thick succession of mainly siltstones and sandy limestones (3). A combined biostratigraphy based upon graptolites, cryptospores and conodonts indicates that Package 1 is of Llandovery (Rhuddanian, Aeronian and/or early Telychian) age, Package 2 …


Preservation Of The Seismic Cycle In A Continental Low-Angle Normal Fault: West Salton Detachment Fault, Usa, Mitchell R. Prante, Susanne U. Janecke, James P. Evans Jan 2012

Preservation Of The Seismic Cycle In A Continental Low-Angle Normal Fault: West Salton Detachment Fault, Usa, Mitchell R. Prante, Susanne U. Janecke, James P. Evans

Geosciences Presentations

No abstract provided.


Nebraska - Epa Map Of Radon Zones, Us Environmental Protection Agency Jan 2012

Nebraska - Epa Map Of Radon Zones, Us Environmental Protection Agency

United States Environmental Protection Agency: Publications

The purpose of this map is to assist National, State and local organizations to target their resources and to implement radon-resistant building codes.

This map is not intended to determine if a home in a given zone should be tested for radon. Homes with elevated levels of radon have been found in all three zones.

All homes should be tested, regardless of zone designation.


Post-Speleogenetic Biogenic Modification Of Gomantong Caves, Sabah, Borneo, Joyce Lundberg, Donald A. Mcfarlane Jan 2012

Post-Speleogenetic Biogenic Modification Of Gomantong Caves, Sabah, Borneo, Joyce Lundberg, Donald A. Mcfarlane

WM Keck Science Faculty Papers

The Gomantong cave system of eastern Sabah, Malaysia, is well-known as an important site for harvesting edible bird-nests and, more recently, as a tourist attraction. Although the biology of the Gomantong system has been repeatedly studied, very little attention has been given to the geomorphology. Here, we report on the impact of geobiological modification in the development of the modern aspect of the cave, an important but little recognized feature of tropical caves. Basic modeling of the metabolic outputs from bats and birds (CO2, H2O, heat) reveals that post-speleogenetic biogenic corrosion can erode bedrock by between …


Climate Divisions For Alaska Based On Objective Methods, Peter A. Bieniek, Uma S. Bhatt, Richard L. Thoman, Heather Angeloff, James Partain, John Papineau, Frederick Fritsch, Eric Holloway, John E. Walsh, Christopher Daly, Martha Shulski, Gary Hufford, David F. Hill, Stavros Calos, Rudiger Gens Jan 2012

Climate Divisions For Alaska Based On Objective Methods, Peter A. Bieniek, Uma S. Bhatt, Richard L. Thoman, Heather Angeloff, James Partain, John Papineau, Frederick Fritsch, Eric Holloway, John E. Walsh, Christopher Daly, Martha Shulski, Gary Hufford, David F. Hill, Stavros Calos, Rudiger Gens

National Drought Mitigation Center: Faculty Publications

Alaska encompasses several climate types because of its vast size, high-latitude location, proximity to oceans, and complex topography. There is a great need to understand how climate varies regionally for climatic research and forecasting applications. Although climate-type zones have been established for Alaska on the basis of seasonal climatological mean behavior, there has been little attempt to construct climate divisions that identify regions with consistently homogeneous climatic variability. In this study, cluster analysis was applied to monthly-average temperature data from 1977 to 2010 at a robust set of weather stations to develop climate divisions for the state. Mean-adjusted Advanced Very …


Drought Monitoring: Historical And Current Perspectives, Michael J. Hayes, Mark D. Svoboda, Brian D. Wardlow, Martha C. Anderson, Felix Kogan Jan 2012

Drought Monitoring: Historical And Current Perspectives, Michael J. Hayes, Mark D. Svoboda, Brian D. Wardlow, Martha C. Anderson, Felix Kogan

National Drought Mitigation Center: Faculty Publications

Drought is a normal, recurring feature of climate throughout the world, with characteristics and impacts that can vary from region to region. Figure 1.1 illustrates the regular occurrence of drought within the United States between 1895 and 2010 with approximately 14% of the country, on average (plotted by black dotted line), experiencing severe to extreme drought conditions during any given year. Drought conditions can persist in a region for several years, as occurred in the United States in the 1930s, 1950s, and early 2000s, and tree ring and other proxy records confirm that multiple-year droughts are part of the long-term …


Future Opportunities And Challenges In Remote Sensing Of Drought, Brian D. Wardlow, Martha C. Anderson, Justin Sheffield, Bradley D. Doorn, James P. Verdin, Xiwu Zhan, Matthew Rodell Jan 2012

Future Opportunities And Challenges In Remote Sensing Of Drought, Brian D. Wardlow, Martha C. Anderson, Justin Sheffield, Bradley D. Doorn, James P. Verdin, Xiwu Zhan, Matthew Rodell

National Drought Mitigation Center: Faculty Publications

The value of satellite remote sensing for drought monitoring was first realized more than two decades ago with the application of Normalized Difference Vegetation Index (NDVI) data from the Advanced Very High Resolution Radiometer (AVHRR) for assessing the effect of drought on vegetation, as summarized by Anyamba and Tucker (2012, Chapter 2). Other indices such as the Vegetation Health Index (VHI) (Kogan, 1995) were also developed during this time period and applied to AVHRR NDVI and brightness temperature data for routine global monitoring of drought conditions. These early efforts demonstrated the unique perspective that global imagers like AVHRR could provide …


Microwave Remote Sensing Of Soil Moisture Science And Applications, Son V. Nghiem, Brian D. Wardlow, David Allured, Mark Svoboda, Doug Lecomte, Matthew Rosencrans, Steven K. Chan, Gregory Neumann Jan 2012

Microwave Remote Sensing Of Soil Moisture Science And Applications, Son V. Nghiem, Brian D. Wardlow, David Allured, Mark Svoboda, Doug Lecomte, Matthew Rosencrans, Steven K. Chan, Gregory Neumann

National Drought Mitigation Center: Faculty Publications

Soil moisture is a fundamental link between global water and carbon cycles and has major applications in predicting natural hazards such as droughts and floods (National Research Council, 2007). From precipitation data, soil wetness can be estimated by hydrological land-surface models. In the United States, preliminary precipitation data are based on measurements gathered from many active stations nationwide each month, and it takes 3–4 months to assemble final, quality-controlled data. In the western United States, some climate divisions may have no stations reporting in a particular month or may lack first- or second-order stations, and significant blockages by mountains limit …


Drought Triggers And Declarations: Science And Policy Considerations For Drought Risk Management, Linda Courtenay Botterill, Michael J. Hayes Jan 2012

Drought Triggers And Declarations: Science And Policy Considerations For Drought Risk Management, Linda Courtenay Botterill, Michael J. Hayes

National Drought Mitigation Center: Faculty Publications

This paper explores the value of triggers and declarations in the management of drought, bringing together two disciplinary perspectives, those of the public policy scholar and the climate scientist. These two perspectives highlight the complexity of the development and use of triggers in drought risk management by drawing on the experience of the United States, which has the most sophisticated system of drought triggers in the world, and that of Australia that has the most developed and longest standing national drought policy based on principles of risk management. The paper explores the advantages and disadvantages of triggers in managing drought, …