SDSU Oceanography100 (Exam 3) Questions And Answers 100% Verified

SDSU Oceanography100 (Exam 3) Questions And Answers 100% Verified What are the parts of a coastal region? - answerCoast, offshore, beach, berm, notch, wave- cut platform What does wave energy do to a coastal cliff over time? - answerWave Energy erodes the cliff, eventually creating sea stacks, caves and arches What do rivers and cliff erosion have to do with sand to the berm? - answerRivers: some carry more sediment to the ocean than longshore currents Cliff Erosion: sediments erode to join the berm How is the sand supply in Southern California? - answerBecause of seawalls, the production of sand is decreasing What is the principle source of sand supply in Southern California? - answerThe soft-rock cliffs What is the significance of the berm? - answerThe berm is where the eroded sediments are, and they are now moving with the ocean Wintertime vs Summertime Beaches - answerWintertime: larger, high energy waves scour sand from the berm Summertime: lower energy waves move sand up the beach face, toward the berm Definition: Longshore current - answerThe zigzag movement of water along the shore, parallel to the coast Definition: Longshore drift - answerThe movement of sediment in a zigzag fashion caused by the longshore current Why are there longshore currents and longshore drifts? - answerThe waves approach the beach at an angle Which direction does the current push the sand in terms of longshore current? - answerDown-coast in a zigzag motion; South Which direction does sand move in Southern California in terms of longshore current? - answerFrom North to South What are the characteristics of an Erosional Coast? - answerwell developed cliffs, sea caves, sea arches, marine terraces, wave-cut cliffs Are in areas where tectonic uplift of coast occurs What are the characteristics of a Depositional Coast? - answershore gradually subsiding, spits, bay barriers, tombolos, barrier islands How do erosional and depositional coasts tie in with plate tectonics? - answerActive tectonics lift the plates up Contrast the Atlantic and Gulf to the Pacific Coasts; sea level changes and effect - answerAtlantic: depositional; passive margin; no plate boundary Pacific: Erosional; active margin; Shoreline rises and ocean does not migrate inland Gulf: below sea level; ocean would migrate the farthest inland What are the causes of global sea-level changes? - answerRaising or lowering of the land surface relative to the sea level through movement of Earth's crust How does tectonics (MOR activity) affect sea levels? - answerUplift or subsidence of major portions of continents or ocean basins How does climate affect sea levels? - answerThermal Contraction lowers sea level Thermal Expansion raises sea level What happens if all ice melts on Earth? - answerSea level rises by 70 meters, waters will warm up quicker What areas of the U.S. will be affected most if all ice on Earth were to melt? - answerMemphis and the South Coast because it is very flat How do we change the coastline in an Ice Age vs Global Warming? - answerIce Age: Coastline will grow Global Warming: Coastline will shrink People build houses right on the berm...how? What happens during storms? - answerPeople build houses on the berm by using stills. During storms, the berms are flooded and the homes will be destroyed due to high tides, tsunamis, and swells