1) What happens to global eustatic sea level during glacial periods…

Question Answered step-by-step 1) What happens to global eustatic sea level during glacial periods… 1) What happens to global eustatic sea level during glacial periods when large ice caps grew on the high latitude regions of continents?  And then what happened when these ice caps melted during interglacial periods?Group of answer choices World sea level goes up when ice caps grow and then drops when ice caps melt. World sea level goes down when they ice caps grow and goes back up when ice caps melt World sea level does not change when ice caps grow or melt. 2)Compared to today, how much lower (in vertical feet) was global eustatic sea level 20,000 years ago during the Last Glacial Maximum (low-stand)?    Group of answer choices 20 feet lower than today 500 feet lower than today 400 feet lower than today 300 feet lower than today 120 feet lower than today 3) How many major glacial-interglacial cycles have occurred during the last 500,000 years?  Hint:  Look at the ice age graph and count the number of major (maxiumum peaking) high-stands (including the current one going on right now).Group of answer choices 2 major cycles 4 major cycles 6 major cycles 1 really big one. 8 major cycles 10 major interglacial cycles 4) About how much (in vertical feet) did world sea level change (absolute amount between low-stand and subsequent high-stand) during the biggest of the glacial interglacial cycles over the last 500,000 years?   Hint:  The largest one occurred between roughly 150,000 to 100.000 years ago.Group of answer choices 220 feet 430 feet 100 feet 580 feet 20 feet 5) You have seen how global eustatic sea level has gone up and down during the last several hundred thousand years, due to the ice ages.What about the land in Southern California?  Has the land been mostly rising upward, subsiding (sinking downward), or staying at the same topographic level? Group of answer choices Land has risen (uplifted) Land has dropped (subsided) Land has been stable – no vertical movement There is no way to tell if the land is vertically changing 6) What is the name of the marine terrace that has an age of 80.000 years?  Hint:  It gets its name from the type location in La Jolla.Group of answer choices Guy Flemming Nestor Black Mountain Bird Rock Stuart Mesa 7) What is the elevation of the San Elijo marine terrace?  Hint:  Its one of the 5 lowest/youngest marine terraces in San Diego.Group of answer choices 95 feet 456 305 feet 223 feet 630 feet 8) What is the connection/relationship between a marine terrace’s age and the marine terrace’s elevation? Group of answer choicesThe older the marine terrace, the lower the elevation. The older the marine terrace, the higher the elevation. The younger the marine terrace, the higher the elevation. There is no connection between marine terrace age and elevation. 9) How are our coastal marine terraces formed?  Note:  Each of the possible answers are lengthy explanations.  Take your time and read through each one, while thinking about what you learned about marine terraces, in terms of when a terrace orginally formed at sea level during a specific part of a glacial cycle and how vertical land motion was involved. Group of answer choices Marine terraces are formed by a combination of tsunami, tides, eustatic sea level fluctuations, and up-down tectonics. A shoreline will get beveled by a very large tsunami and become a wave-cut platform. Then the tides will cause the sea level to reach a high-stand, while the land is uplifting. Sea level will eventually drop to a low-stand level when the tide goes out, and the wave-cut platform is then left high and dry. When the land starts to subside, the wave-cut platform that was created from the last high-stand is no longer at the high-stand sea level position because during the elapsed time the land uplifted agian. Subsequently, when the land starts to uplift, and the newest wave built bench that had been lifted below the latest high-stand sea level and now becomes the youngest, newest marine terrace. As time goes on, this cycle will repeat to make even newer, younger marine terraces. Older wave-built platforms have had even longer time get lowered and lifted even more. Therefore, the oldest wave-cut platforms will now be the lowest and highest marine terraces. Marine terraces are formed by a combination of shoreline deposition, sea level fluctuations, and land subsidence. Wave-built platforms or benches are actively built up along the shoreline by wave action (causing coastal beach sand build-up), while sea level is at a low-stand. Sea level will eventually rise back to a high-stand level, and the wave-built platform is then left high and dry. When the eustatic sea level drops back down up to a low-stand during the next interglacial cycle, the wave-built platform that was created from the last low-stand is no longer at the low-stand sea level position because during the elapsed time from the last low-stand to the current one, the land has been slowly subsiding. Subsequently the newest wave built bench has been lowered below the latest low-stand sea level, and has now become the youngest, newest marine terrace. As time goes on, this cycle will repeat to make even newer, younger marine terraces. Older wave-built platforms have had even longer time get lowered even more. Therefore, the oldest wave-cut platforms will now be the lowest marine terraces, and also the ones furthest out to sea. Marine terraces are formed by a combination of receding shoreline erosion, sea level fluctuations, and uplift. Wave-cut platforms or benches are actively cut along the shoreline by wave action (causing coastal retreat), while sea level is at a high-stand. Sea level will eventually drop back to a low-stand level, and the wave-cut platform is then left high and dry. When the eustatic sea level rises back up to a high-stand during the next interglacial cycle, the wave-cut platform that was created from the last high-stand is no longer at the high-stand sea level position because during the elapsed time from the last high-stand to the current one, the land has been slowly uplifting. Subsequently the newest wave cut bench has been elevated above the latest high-stand sea level, and has now become the youngest, newest marine terrace. As time goes on, this cycle will repeat to make even newer, younger marine terraces. Older wave-cut platforms have had even longer time get uplifted even higher. Therefore, the oldest wave-cut platforms will now be the highest marine terraces, and also the furthest inland. Marine terraces are formed by a combination of shoreline longshore drift, sea level fluctuations, and land elevation fluctuations. Wave-cut platforms or benches are actively formed along the shoreline by the tides while sea level is at a high-stand and the land is subsiding. Sea level will eventually drop to a low-stand level, and the wave-cut platform is then left high and dry. When the land starts to subside, the wave-cut platform that was created from the last high-stand is no longer at the low-stand sea level position because during the elapsed time from the last high-stand to the current one, the land has been slowly subsiding. Subsequently the land then starts to uplift, and the newest wave built bench that had been lowered below the latest low-stand sea level has now become the youngest, newest marine terrace. As time goes on, this cycle will repeat to make even newer, younger marine terraces. Older wave-built platforms have had even longer time get lowered even more. Therefore, the oldest wave-cut platforms will now be the highest marine terraces, and also the ones furthest out to sea. 10) List the four major coastal processes that have shaped San Diego’s coastal lagoonal valleys.  Hint:  Think about the specific surface processes going on in the coastal river valleys during differnt parts of a galcial cycle. Group of answer choices Sea level fluctuation;  land uplift; longshore drift; and tsunami Waves;  faulting; coastal erosion; and coastal deposition. Sea level fluctuation;  land uplift; coastal erosion; and coastal deposition. Sea level fluctuation;  land subsidence; coastal erosion; and coastal deposition. Tides;  land uplift; coastal erosion; and coastal deposition.  11) How do the various coastal processes work together to form the geography of San Diego’s coastal estuary lagoonal valleys?  HInt:  The professor explained it in the lab orientation video. Group of answer choices During a sea level high stand, the coastal river’s base level shifts seaward to a lower elevation at where the river drains into the ocean. At this time, the coastal river valley is actively built up by deposition (sediments filling in the valley), forming flat, “V” shaped valleys. When sea level drops back down to a low-stand, so does the river base level elevation to where the river meets the ocean (at our present sea level). Active erosion then starts up in the river valley, eventually forming flatter, broader “U” shaped river valleys, where estuaries can develop. During a sea level low-stand, the coastal river’s base level shifts landward to a lower elevation at where the river drains into the ocean. At this time, the coastal river valley is actively built up by deposition (sediments filling in the valley), forming steeper, more “V” shaped valleys. When sea level rises back to a low-stand, so does the river base level elevation to where the river meets the ocean (at our present sea level). Active erosion then starts up in the river valley, eventually forming flatter, broader “U” shaped river valleys, where estuaries can develop. During a sea level high-stand, the coastal rivers’ base level shifts landward to a higher elevation at where the river drains into the ocean. At this time, the coastal river valleys are actively eroded downward (down cut), forming steeper, more “V” shaped valleys. When sea level drops back down to a low-stand, so does the river base level elevation to where the river meets the ocean (at our present sea level). Active erosion ceases in the river valley and is replaced by active sediment deposition (sediments filling up the deep valleys), eventually forming flatter, broader “U” shaped river valleys, where estuaries can develop. During a sea level low-stand, the base level shifts seaward to a lower elevation at where the river drains into the ocean. At this time, the coastal river valley is actively eroded downward (down cut), forming a steeper, deeper, more “V” shaped valley. Then when sea level rises back up to a high stand, so does the base level elevation to where the river meets the ocean. Active erosion ceases in the river valley and is replaced by active sediment deposition (sediments filling up the deep valleys), eventually forming flatter, broader “U” shaped river valleys, where estuaries can develop.  12)What exactly is an estuary? Group of answer choices An estuary is a lagoon.-like body of water that is found in the middle of coral atolls. An estuary is a very productive, lagoon.-like body of water at/near sea level, where ocean water mixes with river fresh water An estuary is a lake filled with salt water that mixes with fresh rainwater. An estuary is any protected coastal body of water that has high primary productivity. An estuary is any water body along the coast that has lots of birds and fish. 13) What are the three main reasons that coastal wetlands/estuaries have such high primary productivity?   Group of answer choices Lots of sun;  lots of animals;  clean water Nutrient-poor;  poor circulation;  deep (poorly-sunlit) water Nutrient-rich;  good circulation;  shallow (well-sunlit) water Clear water;  warm water;  lots of plants  Earth Science Science Oceanography OCEA 101 Share QuestionEmailCopy link Comments (0)