Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

Earth Sciences

PDF

Purdue University

2011

Articles 1 - 6 of 6

Full-Text Articles in Physical Sciences and Mathematics

Solving The Mystery Of The Atacama Nitrate Deposits: The Use Of Stable Oxygen Isotope Analysis And Geochemistry, Ji-Hye Seo Jul 2011

Solving The Mystery Of The Atacama Nitrate Deposits: The Use Of Stable Oxygen Isotope Analysis And Geochemistry, Ji-Hye Seo

The Journal of Purdue Undergraduate Research

The Atacama Desert, Chile, one of the oldest and driest deserts on Earth, is unique because it contains the largest known nitrate deposits in the world. The origin of these nitrate deposits has been a mystery since their discovery in the 1800s. There are two possible sources of natural nitrate: microbiological processes and photochemical reactions. The majority of material on Earth follows mass-dependent fractionation between stable oxygen isotopes with the abundance of 17Ο (denoted by δ) as half that of 18O. This relationship is quantified by Δ17O = δ17O – ½ δ18O, …

Go to article

The Use Of Large-Scale Climate Data To Predict Drought, River Flows, And Vegetation Over Central-Southwest Asia, Matthew Barlow Jun 2011

The Use Of Large-Scale Climate Data To Predict Drought, River Flows, And Vegetation Over Central-Southwest Asia, Matthew Barlow

2011 Symposium on Data-Driven Approaches to Droughts

Central-Southwest Asia is a semi-arid, economically stressed region where droughts have severe societal impacts in terms of agriculture, farming, access to fresh water for drinking, and sanitation. There are two sources of drought predictability for this area: the influence of predictable modes of large-scale climate variability at both seasonal and intraseasonal timescales, and the importance of the snow pack to warm season river flows and vegetation. Local data scarcity is a critical problem for the region, both for historical analysis and for real-time monitoring. However, analysis shows that satellite data can be used to provide a considerable amount of high-resolution …

Go to article

Climatic Characterization And Response Of Water Resources To Climate Change In Limestone Areas: Some Considerations On The Importance Of Geological Setting, Di Matteo Lucio, Valigi Daniela, Cambi Costanza Jun 2011

Climatic Characterization And Response Of Water Resources To Climate Change In Limestone Areas: Some Considerations On The Importance Of Geological Setting, Di Matteo Lucio, Valigi Daniela, Cambi Costanza

2011 Symposium on Data-Driven Approaches to Droughts

It is worldwide recognized and accepted that, in Southern Europe and the Mediterranean area in the last hundred years, the atmospheric temperature has risen by about 1°C, accompanied by a general decrease in precipitation. The trends detected in historical thermo-pluviometric series recorded in South/Central Italy show a general decrease in precipitation on an annual scale and a concentration of negative trends in the months from October to March. Analysis of the Standard Precipitation Index for the period 1951-2008 indicates higher frequency and duration of droughts in the last two decades: four prolonged dry periods (each lasting for up to three …

Go to article

Monitoring Drought Across Many Scales, Chris Funk Jun 2011

Monitoring Drought Across Many Scales, Chris Funk

2011 Symposium on Data-Driven Approaches to Droughts

Monitoring drought across many scales Chris Funk As gas and food prices increase while per capita harvested area decreases, drought and disruptions in food availability exert more and more pressure on the political and economic stability of ‘frailed’ states. Improved drought monitoring across many spatial and temporal time scales has therefore become increasingly important. As this need mounts, so have our capacities to observe and understand the earth’s climate. Relatively new satellite systems, such as the Moderate Resolution Imaging Spectrometer, allow us to watch the earth at scales of ~100 meters. Improved rainfall retrievals give us more timely and accurate …

Go to article

An Update On Noaa’S National Integrated Drought Information System, Doug Kluck Jun 2011

An Update On Noaa’S National Integrated Drought Information System, Doug Kluck

2011 Symposium on Data-Driven Approaches to Droughts

NOAA through the National Integrated Drought Information System (NIDIS) supports planning and early warning preparedness amongst communities and states. Since the inception of NIDIS in 2006 there have been a series of regional drought projects across the United States that have begun to help different groups renew or begin to plan for drought. This presentation will briefly touch upon some of the successes those pilot projects have achieved and where they are headed. In addition and overview of NIDIS and the drought portal will be included.

Go to article

Crustal Structure Across The Central Alaska Range: Anatomy Of A Mesozoic Collisional Zone, P.R.K. Brennan, H. Gilbert, K. D. Ridgway Jan 2011

Crustal Structure Across The Central Alaska Range: Anatomy Of A Mesozoic Collisional Zone, P.R.K. Brennan, H. Gilbert, K. D. Ridgway

Department of Earth, Atmospheric, and Planetary Sciences Faculty Publications

A first-order process in the growth of continents is the collision and accretion of terranes against continental margins. Collision leads to the formation of a suture zone between the accreted terrane and the former continental margin. New insights on the suturing process are observed from two receiver function transects across the Mesozoic Alaska Range suture zone. Three distinct crustal sections are identified from observations of crustal thickness, intracrustal discontinuities, and Vp/Vs: a northern section with ∼27 km thick crust of felsic to intermediate composition, a central section that is ∼37 km thick that exhibits intracrustal discontinuities and has felsic to …

Go to article