Earthquake Disasters: Sylmar Earthquake III Aftershocks & Landslides

An inspection that lasted for three weeks studying the aftershocks was done by the Californian Institute of Technology. The events that were being included in the study were events that have been recorded by various stations. An USGS instrument was situated at the Point Mugu and California’s Department of Water Resources which were seismometers at the Pyramid Springs and the Cedar Springs. The seismometers that were stationed temporarily were set up as a response to the main shock was functioning within the six to seven days after the earthquake. It had provided data in addition the previous ones until the 1st day of March. The item catalog was almost entirely complete and included about 200 shocks with a magnitude of 3.0 and above. About 4 of the shocks were measured to have a magnitude of 5.0 and above. In the first hour of the activity, the smaller events were overshadowed by the much larger aftershocks.

The general patter of the aftershock appeared in the figure of a symmetrically inverted U although it had a bit more concentrated events on the flank of the southwestern part. Seven of the shocks that were smaller had approached the faulting’s area of surface although for most of the part, the part that had experiences the most shaking and had taken the most damage had lacked aftershock activity. The Pacoima Dam’s high peak ground acceleration reading was very near to the middle of the aftershock free zone.

The USGS had commissioned a private company along with the U.S. Air Force to get aerial photographs above the 97 square mile mountain area north of San Fernando Valley. The analysis had showed that the earthquake had triggered about 1,000 and more landslides. Shattered rock were also documented on the ridge top area and the rock-falls, it seemed to be the effects the combined power of an aftershock and an initial shock. A few of the data that were recorded aerially were being studied from the ground as well. The most number of slides that were centered to the southwestern part of the epicenter of the main shock and near the areas where the surface faulting had taken place. The slides had ranged from 49 feet up to 984 feet or 15 meters to 300 meters in length, and could be categorized as slumps, rock falls, decries slides, soil falls, and avalanches. The most commonly encountered type of slide is the surficial debris slide. These types of slides were most common on terrains that are made up of sedimentary rock.

These occurrences, although tragic are being used as a wakeup call for people to make an action towards safety awareness. Sometimes we can say that it is the shortcomings of our experts that contribute to the overall damage of the earthquake. But these experts are also the same exact people who help the public understand what is going on under them. They are also

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