Detecting El NiÃo in Sea Surface Temperature Data
SST anomalies for December 1997 displayed in My World GISâ. Red indicates above average temperatures compared to average SST temperatures for December data averaged over the years 1982-1998. This chapter introduces you to normal seasonal sea surface temperature (SST) variation as well as extreme variation, as in the case of El NiÃo and La NiÃa events, in the equatorial Pacific Ocean. You will learn how to download seasonal SST data from the Pacific Marine Environmental Laboratory (PMEL), via a THREDDS server, for the years 1982 to 1998. With My World GIS, you will visualize and analyze that data, looking for the tell-tale SST signature of El NiÃo and La NiÃa events that occurred during that time period. At the conclusion of the chapter, you will be given the opportunity to analyze a season of your own choosing to determine if an El NiÃo and La NiÃa SST pattern emerged in that year's data.

Earth From Space: Earth's Water Habitats

This search engine allows users to search a database of NASA satellite images of all Earth's water habitats including everything from oceans to ice. Users may select water habitats from a list and set search output parameters to show results as thumbnails, graphically intense images or text only. Due to the abundance of images in the database, searches may take a moment.

Dryland Rivers Research

This site is intended to stimulate research by providing an information focus and provoking networking between those working on dryland rivers and the sediments they leave behind. Topics covered include processes and products, hydrology, dynamics, architecture of rivers and their floodplains, adjacent and interacting processes, modern and ancient dryland rivers and integration of geomorphology and sedimentology. Users may follow links to dryland river descriptions and myths, hot topics, a discussion forum, images and other useful information.

Weathering - Part I

This site features 27 different photographs of physical, mechanical, and chemical weathering of outcrops and man-made structures.

Chemical Weathering of Feldspar to Clay

This site features a short animation that shows the evolution of an unaltered feldspar crystal to a clay as a result of progressive chemical weathering. The animation can be paused and rewound to emphasize important points associated with the content. As the clip rolls, captions explain what viewers are observing.

Weathering and Mineral Evolution

This annotated slide set shows how the introduction of rain water changes the elemental composition of parent material as it is weathered into first immature and then mature soil. The site illustrates and explains the chemical weathering of aluminum, iron, silicon, calcium, magnesium, sodium, and potassium minerals under minimal, moderate, and intensive weathering conditions. Captions also explain in which climates each type of weathering occurs.

Weathering and Clay Evolution

This annotated animation shows how primary minerals lose content at a linear pace. The site illustrates how primary minerals, 2:1 clays, 1:1 clays, and aluminum and iron oxides develop as a function of time.

Mineral Weathering

This annotated animation explains how chemical weathering affects the evolution of parent material from highly resistant primary minerals to both secondary minerals and minerals in solution. It illustrates how, over time, weathering changes both the elemental and the mineral composition of soil.

Examples of Physical Weathering

This site provides six photographic examples of physical or mechanical weathering. Included are three examples of frost wedging and three examples of root wedging. Clicking on each example yields a larger view.

Surface Area vs. Size and Shape

This annotated animation shows the potential increase in surface area which results from physical weathering. Students have the opportunity to calculate and compare surface area increases for two different scenarios: when a single mass weathers into cubical blocks versus plate-like blocks. Captions help students through calculations for determining the total surface areas of the different shapes.