Developing a Quaternary geological map in flood prone areas, typically on alluvial fans was recognized by the National Research Council (NRC, 1996) and by FEMA in there 2003 guidebook. FEMA region IX gave the California Department of Water Resources the responsibility of monitoring and tracking alluvial fan hazards (FEMA, 2003). The California Department of Water Resources has an Alluvial Fan Task Force (AFTF) so that there would more research on alluvial fans and how they contribute to flood hazards (Benrossian, T.L, 2014). They have map 10 counties in southern California in developed areas seen in figure 2. However, there are no detailed maps on Quaternary deposits in unincorporated areas.
The unincorporated area of Salton Sea Beach, Imperial
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In the upper corer of the topo map, it shows the same feature that was observed in figure 6, figure 7 and figure 8, where the ancient shoreline of the Salton Sea once resided. Southwest of the topo map is shows contours lines evenly space-out and directional flow of small channels which is evident of flash flooding. So, that area is a flood plain or a sheet flow that has eroded the base of the alluvial fan. The alluvial fan is very distinctive in the topo map where the active channel flows downstream through a laterally confined mountainous valley that cuts through the alluvial fan, ancient shoreline and bleeds to a non-confined lowland of the flood …show more content…
Characterizing the morphology of the alluvial fan with the 1-meter DEM will help to further delineate the evolution of the fan. Two profiles of the alluvial fan were analyzed by creating traces along the alluvial fan seen in figure 3b and figure 3c. The elevation of figure 3b and figure 3c was traced with ArcGIS and calculated using MatLab. The cross-sections of the alluvial fan show the curvature of the fan morphology. These traces align in the west - east direction shown in figure 3b that corresponds to the profile of figure 11. Figure 3c alignment is in the north - south direction and corresponds to profile figure 12. Where the traces end, it marks the change of the slope profile of the fan. It is difficult to see but the cross-section from a to g starts out convex to concave retrospectivity. According to Stock J.D. (2008) how sediments are transported; longer profiles are commonly concave up and the shorter fans are generally convex. In contrast, the cross-sections of figure 9 show how the sediments are dispersed. There is higher density of material in profile A and has a slight convex morphology. As you move towards profile G a slight concave morphology can be
flood. However, Phillip Flat is located center of the other three lands and it makes
One of the major things noticeable from the cross section is that quite a few of the rock layers are over turned, where the older rock layers are above the newer rock layers. This is seen in the contact between the Quartz Monzonite of Papoose Flat and the Campito Formation which is also a disconformity. Next there is some fault zones separating the Camptio, Poleta, and Harkless formations. We then see some more overturned layers with the contacts between Saline Spring Valley Formation (lower and upper members) above the Mule Spring Formation along with some inferred folding. With a normal fault separating the inferred folding event, we see where the overturning occurs. In between the Cambrian layers we see Tertiary Basalt nonconformities also being folded, thus with that we know that the folding event was more recent than the formation of the Basalt. Next there is a large Basalt field with a spot of the Harkless formation. Again we see over tuning as the Basalt field ends there are the Devonian and Mississippian rock Layers on top of the basalt. Separating these overturned layers from the Harkless Formation and the Saline valley Formation (upper member), which are not overturned, is a thrust fault. From this information, there was a major stress event sometime after the Tertiary period causing the rock layers to fold and overturn. And from this stress event and from the folding, normal and thrust faults are formed. Finally we see that there were alluvial and landslide deposits from the Quaternary after the folding, faulting, and over
Questions and charts are from Geoscience Laboratory, 5th ed. (p. 133-150), by T. Freeman, 2009, New York, NY: John Wiley & Sons. Reprinted with permission.
10. This Figure 3 vertical cross-section exhibits a profile consistent with a tectonically [(passive)(active)] coastal region.
The formation of San Diego region involved numerous activities which varied from volcano activities, the formation of Gulf, uplifting and tilting among others. These activities happened in a long span of time creating three distinct geomorphic regions: the west of peninsular rangers, peninsular ranges region, and the Salton Trough region. The geomorphic division reflects the basic difference amid geographic parts containing Mesozoic metavolcanic, metasedimentary, and plutonic rock material. The development of these features resulted to the occurrence of the current San Diego state. The integration of different rocks, volcanic activities, and subduction processes resulted to the development of peninsular region and Salton Trough.
There are coarsening-upward sequences preserved, with flooding surfaces represented by low-relief erosional contact of trough-cross-stratification (runnel) upon low-angle planar bedding (swash zone).
The west coast of North America has been tectonically and volcanically active for billions of years. The Sierra Nevada Mountains in eastern California were born of volcanoes, and magma has been erupting in the Long Valley to the east of the mountains for over three million years (Bailey, et. al., 1989). However, the climactic eruption of the region occurred relatively recently in the region's geologic history. About 760,000 years ago, a huge explosion of magma warped the Eastern Sierra into the landscape that exists today. The eruption depleted a massive magma chamber below the earth's surface so that the ceiling of the chamber imploded, forming what is now known as
They have sinuous, curving channels and their heights are higher compared to their widths (Thompson & Thompson, 2003). Irregularities toward the local direction of slant cause paths sinuosity. Canyons located in the Mammoth Cave run up to 80 to 100 feet high and 10-30 feet wide but many of them are not that high and much narrower. Vertical shafts are created where water can run down vertically alongside fractures (Call, 2010) as illustrated in figure 6.
* The Skillion, mainly the headland and rock platform, which is part of a preserved area of land known as “the Haven” which also contains the rugby oval. The man type of erosion that affects this is from the sea.
Especially in the area around the Great Basin, since that covers most of the state. This area is surrounded by the mountain ranges and gets all the run off . This water helps with the water shortage throughout the year but at the time it is too much for the area to handle as there is no drainage to the ocean from this area. Groundwater is used throughout the state. Sometimes, the water is pumped out faster than it can be replenished. When this happens, the land surface can be affected. There are many cracks in the ground near Las Vegas, and in some places the land has sunken in over six feet within the last sixty years. An increase in the population of the state is to blame for the increased demand on the groundwater and therefore, the increased damage being done to the landscape as a whole. More people, more water, more land being developed, means less of the natural preservers being available. Also, with these floods the state sees landslides. The rocks of the area show the different ways the terrain was built
The Raton Basin is a structural basin situated in Las Animas and Huerfano counties of southeastern Colorado, and Colfax County of northeastern New Mexico (Speer, 1976). Although millions of years ago the Raton Basin was much different than the present. Colorado and New Mexico were covered by large shallow seas (Murray, 1978). The Basin is bounded on the west by the Sangre de Cristo Mountain range and on the east by two subsurface elements, the Apishapa Arch and the Sierra Grande Uplift. The Apishapa Arch is a northwest-southeast oriented structural extension of the Wet Mountain Uplift which terminates the basin on the northeast, whereas the Sierra Grande Uplift is a northeast-southwest oriented subsurface arch that forms the basin 's
Going to put in forty hours of work a week and not getting paid? That sounds completely crazy right. Think about it, that is how most college athletes are living. Or are they getting payment with the education they are receiving? Athletes bring in most of the big university’s money, but get nothing.
The Central Valley of California, United States, is a notable structural depression which covers around 32,187km2 (Figure 1), and is bounded by the Cascade Range in the north, the Sierra Nevada in the east, the Tehachapi Mountains to the South, and the Coast Ranges and San Francisco Bay to the west (Planert 1995).
I have researched the effect of climate change on California’s natural water supply. California has a diverse climate throughout, being a large state with sixteen different climate zones recognized. These can be subdivided into four major climatic zones as follows: North Coast, South Coast, Central Valley, and Desert/Mountain.
Water from the south then flowed in over time, thus forming the evaporites now found along the coastlines there. (Lois Van Wagner, 2013)(Figure 5)