Contrary to popular belief, California will not suddenly "fall into the ocean." It will just continue moving at about 2 inches per year until, 15 million years from now, Los Angeles will be located right next to San Francisco. The southwestern portion of California is moving northwestward towards Alaska. While strike-slip faults occur across the world, the most famous is the San Andreas fault. That means someone standing near the fault trace and looking across it would see the far side move to the right or to the left, respectively. Strike-slip faults are either right-lateral or left-lateral. The forces creating these faults are lateral or horizontal, carrying the sides past each other. If the block moving toward you is the block that your right foot is on, the fault is known as a right-lateral strike-slip fault. In these faults, the fault plane is usually vertical so there is no hanging wall or footwall. Left-lateral strike-slip fault If the land moves to the left it is a left-lateral strike slip fault. That is, the slip occurs along the strike, not up or down the dip. Right-lateral strike-slip fault If you look across a fault zone and it looks like the rivers and valley on the other side have moved horizontally to the right the fault is a right-lateral strike-slip fault. On extensional duplexes, normal faults will accommodate the vertical motion, creating negative relief. Strike-slip faults have walls that move sideways, not up or down. Right lateral motion of a strike-slip fault at a right stepover (or overstep) gives rise to extensional bends characterised by zones of subsidence, local normal faults, and pull-apart basins. jack0m/DigitalVision Vectors/Getty Images Rake>0 means the hanging wall moved up (thrust or reverse fault).Strike-slip faults occur as plates scrape by each other. They are mainly vertical, strike-slip faults separating strips of lithosphere with predictable age, thermal and relative strength relationships. Rake=0 means the hanging wall, or the right side of a vertical fault, moved in the strike direction (left lateral motion) Rake = +/-180 means the hanging wall moved in the opposite direction (right lateral motion). Rake - the direction the hanging wall moves during rupture, measured relative to the fault strike (between -180 and 180 decimal degrees). Faults which move horizontally are known as strike-slip faults and are classified as either right-lateral or left-lateral. Strike-slip faults happen when two plates move horizontally past each other. 5.0 and larger events have occurred to its east. Strike-slip Faults: Sometimes referred to as a lateral fault, this type forms when the blocks of. This zone of right-lateral strike-slip becomes transpressional at its eastern end, with the development of large thrust faults. Reverse faults occur when one plate slides under the other, creating a vertical offset. Reverse faults often form along convergent plate boundaries. A strike-slip, or lateral, fault is one in which the movement is horizontal, parallel to the strike of the fault plane. Normal faults occur when two plates, one on top of the other, slide past each other and create the fault. For a vertical, strike slip fault (for which “hanging wall” has no physical meaning) we still call the right-side block the hanging wall to distinguish between right lateral and left lateral motion.ĭip - the angle of the fault in decimal degrees (0 to 90, relative to horizontal). There are three types of faults that may occur in a rock. This is important because rake (which gives the slip direction) is defined as the movement of the hanging wall relative to the footwall. Strike-slip faults involve motion which is parallel to the strike of the fault-frequently described as a 'side-by-side' motion. This means that the hanging-wall block is always to the right. That is, the fault always dips to the right when moving along the trace in the strike direction (from one point to the next). Major lateral offsets between large extensional or thrust faults are normally connected by diffuse or discrete zones of strike-slip deformation allowing the. A mini-example of right-lateral strike-slip deformation associated with the 1984 earthquake on Calveras Fault at Hollister the fault is a major splay of the San Andreas transform. The map at left shows a right-lateral strike-slip fault oriented roughly N-S, and the focal mechanism at right represents the fault orientation and the sense of slip on the fault. Strike - the fault-trace direction in decimal degrees (0 to 360, relative to North), defined so that the fault dips to the right side of the trace. (adapted from page 106 of Aki & Richards (1980), Quantitative Seismology - Vol 1 )
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