26, 1998 by Galileo's solid-state imaging system. The image, centered at 66 degrees south latitude and 195 degrees west longitude, covers an area approximately 185 by 125 miles (300 by 203 kilometers). North is to the top of the picture and the sun illuminates the surface from the top. Here on Earth, unlike Europa, large strike-slip faults like the San Andreas are set in motion by plate tectonic forces. Plan view of geometric relations among structures accord- ing to two-dimensional, strike-slip, tectonic models for a vertical fault which strikes N36W (adapted. Daily tidal cycles produce a steady accumulation of lengthwise offset motions. In geology, the terms sinistral and dextral refer to the horizontal component of movement of blocks on either side of a fault or the sense of movement within a shear zone. 1 It forms the tectonic boundary between the Pacific Plate and the North American Plate. The view is of the Earth's surface from above. The San Andreas Fault is a continental right-lateral strike-slip transform fault that extends roughly 1,200 kilometers (750 mi) through the Californias. The San Andreas Fault is an example of a right lateral fault. Then tidal forces close the fault again, preventing the area from moving back to its original position. Schematic illustration of the two strike-slip fault types. strike-slip fault - a fault on which the two blocks slide past one another. These waves contain vital information about the internal structure of the Earth. The structure of the Earth Seismic waves from large earthquakes pass throughout the Earth. Tidal tension opens the fault and subsequent tidal stress causes it to move lengthwise in one direction. Such movement on the faults is generally a response to long-term deformation and the buildup of stress. One theory is that fault motion on Europa is induced by the pull of variable daily tides generated by Jupiter's gravitational tug on Europa. In those cases, the pulled-apart regions can include upwelled materials, but may be filled mostly by sedimentary and eroded material from above. A similar pulling-apart phenomenon can be observed in the geological trough surrounding California's Salton Sea, in Death Valley and the Dead Sea. This upwelling of material formed large areas of new ice within the boundaries of the original fault. This process created openings through which warmer, softer ice from below Europa's brittle ice shell surface, or frozen water from a possible subsurface ocean, could reach the surface. The black line outlines the fault zone, including material accumulated in the regions which have been pulled apart.īends in the fault have allowed the surface to be pulled apart. Videos - Concise video lectures give background information on the Earth and plate tectonics for teaching how earthquakes happen and how they are studied.The red line marks the once active central crack of the fault. Software-Web-Apps - Stand alone software, interactive web tools, and downloadable apps to help you explore seismic data and earthquake topics. The focus of the project is to understand the interaction between strike-slip fault geometry and rupture propagation, from the scale of the laboratory to. Posters - More than just wallpaper, these eye-catching, educative posters invite students to become minds-on with Earth's internal structure, earthquakes, seismic waves and more! Lessons - A step-by-step guide outlining what students will learn across one or more class periods, through a progression of activities, combined in a learning cycle, to achieve the desired student learning. Interactives - Uses interactive Flash (sfw) to illustrate fundamental concepts that are difficult to convey to learners through other means. IRIS offers a range of resources for students, educators and the general public.Īctivities - Bite-sized (5, 15, or 30 minute) demonstrations or student tasks tied to ‘Did You Know?’ questions to engage the learner.Īnimations - Concise animations that illustrate fundamental concepts that are difficult to convey to learners through other means (the real events may be too small, too large, too fast, too slow, or unsafe for the classroom).Ĭourse - A series of lessons that provide the structure for a semester-long undergraduate course.ĭemos - Quick teacher-lead activities (show-and-tell combined with an opportunity for learners to ponder, predict and discuss) to stimulate interest and convey a concept to learners.įact-Sheets- Single page, accessible, discussions of earthquake related topics. Strike-slip faults, by contrast, occur where two pieces of crust are moving horizontally and alongside one another, yielding very little vertical displacement.
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