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.

Weathering - Part I

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

Natural Hazards: Floods

This site contains an interactive map of recent worldwide flood events. Clicking on the icons on the map will display satellite imagery and a detailed description of the flood events. Information in each description includes time and date of the event(s) as well as cause and effects of the event(s). Users may also choose to follow hotlinks to the detailed flood event information. This site is part of NASA's Earth Observatory, Natural Hazards division.

Dynamics of Steady-State Drainage Basins: An Experimental Approach

This site contains animations and data of erosion on a small scale and numerical landscape erosion models. Erosion on small scale models were developed in an erosion facility that allows a miniature landscape to erode through several relief distances at constant base level fall and rainfall rates. Numerical landscape erosion animations are modified from published models with changes to numerical lattice boundaries such as stream curvatures, hillslope failure and directional diffusion. Tables and diagrams provide spatial and temporal statistics of experimental landscapes. Also available on this website are PDF versions of Les Hasbargen's publications and presentations.

Indian Ocean Tsunami Quicktime Animation

This Quicktime animation, by Dr. Steven Ward at the Institute of Geophysics and Planetary Physics at the University of California - Santa Cruz, shows the tsunami's progress across the Indian Ocean. It also shows some water level graphs and wave run-up heights throughout the region.

NOAA East African Coast Tsunami Animation

This NOAA visualization tracks the tsunami waves until they reach the East African coast of Somalia. This Quicktime animation can be paused, rewound and advanced.

The Physics of Tsunamis

This site from the University of Washington includes a Quicktime movie that shows the propagation of the earthquake-generated 1960 Chilean tsunami across the Pacific Ocean. The page also describes the physics of tsunamis through several exploration questions.

My World GIS

My World is a Geographic Information System (GIS) designed specifically for use in middle school through college classrooms. My World provides a carefully selected subset of the features of a professional GIS environment. These features include multiple geographic projections, table and map views of data, distance-measurement tools, buffering and query operations, and customizable map display. They have been selected to provide the greatest value to students without overwhelming them with complexity. The features are accessed through a supportive interface designed with the needs of students and teachers in mind. My World can import data from the industry-standard shapefile format, as well as from tab and comma-delimited text files. In the future, it will be able to communicate directly with GPS-enabled handheld devices. The web site features links to download My World GIS software along with sample data and documentation. This resource is part of the Using Global Data Sets collection. http://serc.carleton.edu/NAGTWorkshops/globaldata02/

Listening to the 2004 Indian Ocean tsunami quake

This resource is an abstract. This study tracks the movement of the rupture that caused the December 26, 2004 Indian Ocean tsunami by comparing recordings of sound waves from five sensors located around the Indian Ocean. The data were used to triangulate the location of sound wave source. Results indicated that the rupture first moved northwest at 2.4 kilometers per second along the Sunda trench then slowed to 1.5 kilometers per second around 600 kilometers from the earthquake's epicenter. The author indicates that the slower speed of the rupture was unusual for an earthquake caused by a rupture close to the surface.

How volcanic eruptions cause tsunamis

This study investigates the effect of pyroclastic flows on tsunami generation. The authors analyzed several possible mechanisms that occur when the particle rich flows encounter water and conclude that the volume and density of the basal flow has a close correlation with the wave's amplitude and wavelength, which can be used to model the water movement in lakes, bays and oceans.