This is a view of the southern end of the Owens valley, CA. Prominent in the center of the figure is a semi-circular volcano with an asymetrical crater that appears to have been breached towards the west. Surrounding the volcano to the south and west is a raised, irregular lava flow which is probably the result of the most recent eruption. To the north and northeast is a much flatter, wider and more extensive terrain which may be an older lava flow. On the western edge of the image the Sierra Nevada Mountainsare evident as a much higher terrain angling NW-SE. In the south central portion of the image there is a large canyon with a west facing escarpment. This canyon may have formed as the rivers carved back into the old lava flows.





P>There are sveral reasons for differences in the elevation information between the NED data the SRTM data. NED maps show the actual height of the ground surface, whereas SRTM data record the canopy (vegetation) which can cause differences in height between the two data sets equal to the height of the vegetation in the region. NED data are generally only vertically acturate to +/- 7 to 15 ft, depending only the quality and resolution of the DEM from which it was made. SRTM data are more current, and thus are also likely to record more recent changes in topography that may not be available in the NED data, which can cause differences in elevation, especially in areas that are undergoing heavy construction or quarrying.









These images are of the western end of Santa Cruz Island, CA. Trending linearly along the edge of the hills is the Santa Cruz Island Fault. It is easily identifiable by the many offset streams which make "dog-legs" as the cross the fault, as well as by the prominent break in slope. The fault forms a long linear valley which trends E-W across the length of the island. The active beach area is bound by marine terraces which are cut by several large drainages. There is also obvious mass wasting (probably by landslides) along the hills near the southern/central end of the beach. North of the fault there are many evenly spaced drainages aleigned N/S flowing southward out of the high hills. To the south of the fault the terrain is significantly different. There are 3 topographically higher regions that trending roughly east west, and have major streams running in between. The differences in character between these two landscapes may be the result of movement along the SCIF juxtaposing 2 very terrains from different areas.