Google Earth provides an easily accessible platform for students to view animations of oceanographic processes created by merging satellite, buoy, and student-built ocean-drifter data. The power of Google Earth is that many oceanographic properties can be displayed simultaneously over time such as atmospheric pressure, winds, surface currents, and sea-surface temperature. Lessons created from these activities address many of the principal outcomes of an introductory oceanography course, including the ability to analyze the interrelationship of ocean processes and understand how modern oceanography relies on technology to observe and measure the state of the oceans. In the classroom, the time-animation effort is paired with a drifter project where students build and release Global Positioning System–equipped drifters and watch their movement via satellite over the Internet. Because students see, touch, and feel the drifter in the classroom as they build and decorate it, they develop an inherent interest in its fate. Following the movement of the drifter fosters student interest in related oceanographic processes, many of which can be animated in Google Earth for the same time period, providing easy comparisons. The satellite data used in these animations are accessed through the National Oceanic and Atmospheric Administration (NOAA) Southwest Fisheries Science Center's ERDDAP (Environmental Research Division's Data Access Program) data server and displayed in Google Earth using keyhole markup language (KML) scripts. Satellite products are downloaded as .png image files and displayed as a series of image overlays to create time animations. Python scripts automate the process of generating KML scripts.

Abstract The San Luis Rey River comprises a 1,450-km2 (560-mi2) watershed in northern San Diego County, California. Construction aggregate has been mined along a 22.5-km (14-mi) reach of the river. Cumulative extraction volumes of eight operators peaked in the late 1980s, with few restrictions or coordinated oversight by local, state, or federal agencies. The river channel was deepened and widened as sand was removed at rates far in excess of natural replenishment. The 1992-1993 floods caused headward erosion of the mined pit boundaries, interruption of sediment transport continuity, and downstream scour. Lowering the base level in the mined portions triggered rapid erosional adjustments in nonmined portions of the river, affecting infrastructure, adjacent property, and wildlife habitat. During the 1992-1993 storms, the riverbed degraded 2.4 to 3.7 m (8 to 12 ft) under the old Route 395 bridge, causing structural instability that closed the bridge to traffic and necessitated a $4.5 million bridge replacement project. The Route 76 bridge over a tributary to the San Luis Rey River failed as the tributary headcut upstream, lowering the bed in the mainstem. The exposure of aqueduct crossings, sewage lines, natural gas conduits, and bridge foundations prompted a comprehensive evaluation of instream mining activity, initiated by the San Diego County Water Authority in 1990. Concurrently, the Environmental Protection Agency authorized funding a watershed management plan to preserve or replace habitat critical to rare, threatened, and endangered species. The lessons learned from the San Luis Rey River include: (1) the cumulative impacts of sand removal should be quantified, and potential offsite impact areas identified; (2) the effects of bed lowering on infrastructure can be quantified and used to limit mining depths and locations; and (3) the loss of riparian habitat can be minimized by identifying affected areas, preserving critical areas, and promptly implementing aquatic habitat and wildlife enhancement programs to restore impacted areas.

Abstract The 1992-1993 winter storms in Murrieta, California, produced rainfall that exceeded 200% of normal. This water infiltrated into buried channels filled with up to 30 m of alluvium and thus added to rising water levels caused by accelerating urban runoff during the previous 5 yr. Downstream valleys in the California Oaks area of Murrieta, now modified to support golf courses, were little affected by the rainfall, for most of the underlying sediments had already been saturated. Upstream, however, nar-row alluvium-filled valleys were subjected to 3 to 4 m of groundwater-level rise in a 2-month period. Depending on local channel geometry and presence of fill loads, the 1992-1993 storms accelerated alluvial saturation, hydroconsolidation of collapsible soils, differential settlement, and formation of ground fissures. This combined natural and man-induced rise in regional groundwater levels damaged many houses and streets and locally impaired underground utilities. Alleged damages exceed $50 million, and litigation continues unabated. The Murrieta (California Oaks) hydroconsolidation, dif-ferential settlement, and ground fissures provide a case study of new challenges to the engineering geologist in California.

Abstract A block-glide debris-fall landslide occurred on February 22,1993, within a 30.5-m (lOO-ft)-high bluff in the Capistrano Beach area in the cities of Dana Point and San Clemente, Orange County, California. Five homes were destroyed, and several others remained in jeopardy subsequent to this catastrophic ground failure. The landslide caused the bluff top to retreat a maximum of 24.4 m (80 ft) and deposited 20,000 m3 (27,000 cy3) of landslide debris up to 10.5 m (35 ft) deep on Pacific Coast Highway (PCH), a designated emergency evacuation route for the San Onofre nuclear-powered electricity generating station. The landslide debris also covered a 76.2-m (250-ft) sec-tion of the only rail line linking the Los Angeles/Orange County area with San Diego. The winter storms preceding this landslide brought 53.3 cm (21 in) of rain to the Capistrano Beach area. The single-month peak of 29 cm (11.44 in) occurred in January and was the highest in 30 yr. This excessive rainfall infiltrated the subsurface, trig-gering the landslide, which failed on an adverse-dipping clay bed at approximately midslope of the 30.5-m (lOO-ft)-high bluffs. The landslide scarp was controlled by high-angle bedrock jointing. Mitigation alternatives were restrictive because of the many public/private landowners involved and the fact that the city boundary between Dana Point and San Clemente is located in the upper part of the bluff. Initially, the various stabilization options considered to reopen PCH were restricted within the jurisdiction of Dana Point. Eventually, the failed portion of the bluff was restored by a system of rock-bolt tiebacks combined with a hardface wall and buttressed slope. Subdrainage was installed along the buttress backcut and behind the hardface wall, and outlets were provided at the slope face.