GEOS 212-1 Homework #4 NAME ___________________________ STUDY GROUP LEADER ____________________________

Currents in the Pacific and Atlantic Oceans

This homework deals with the patterns and rates of surface currents in the Pacific and Atlantic Oceans. To do this exercise you will need to refer to your World Map as well as maps of surface currents sea-surface temperature salinity wind belts Make sure that you turn in only your own work on this exercise! Pacific Ocean currents First, we will trace currents in the Pacific Ocean by following the travels of a ship-load of 29,000 rubber duckies that spilled into the North Pacific in 1992 (http://news.nationalgeographic.com/news/2001/06/0619_seacargo.html). The spill occurred right above the Chinook Trough (located at 42°N, 180°E, marked with an X), within the North Pacific Current, and the duckies have since been carried all around the North Pacific by the surface currents. On the accompanying map, please draw the path a ducky would take from the spill site, past Hawaii, to Japan, assuming that it followed the simplest path along the surface currents. How long would it take a ducky to make this voyage? To do this calculation, assume that the average rate of travel is 50 km/day, measure the distance that the ducky traveled on your full-size World Map (in cm), and then convert the distance to kilometers (multiply by 389 km/cm). This gives you the distance in km, and you know the rate, so solve for time (in days). Show all of your work. What are the names of the main currents that the ducky will travel along? Please show the southernmost position that you would expect a ducky along the west coast of North America -- show this with a big X. Would you expect many duckies to occur along the shores of Australia or South America? Why or why not?

Atlantic Ocean currents In 1999, Tori Murden rowed a small boat across the Central Atlantic, from northwestern Africa to the tip of Florida (http://news.nationalgeographic.com/news/2003/06/0618_030618_torimurdenmcclure.html). It took 81 days, many of which were spent trying to keep her boat from capsizing in large tropical storms. In 1980, Gerard D'Aboville spent 72 days rowing across the North Atlantic in a bathtub! You decide that a real adventure would be to travel in a small rowboat from Miami (Florida) to Capetown (South Africa). Probably best to follow the surface currents as much as possible because rowing against a current is tough work! Please draw a course on the map below that will allow you to follow the surface currents for as much of the voyage as much as possible. What is the approximate temperature of the warmest water you would encounter? ________ What is the approximate temperature of the coldest water you would encounter? ________ Write these values on the map where you would experience the warmest and coldest water. What is the approximate salinity of the saltiest water you would encounter? ________ What is the approximate salinity of the least salty water you would encounter? ________ Write these values on the map where you would experience the saltiest and least salty water. Please draw arrows on your map that show the average direction the wind would be blowing along your voyage. Label each of the main wind belts. What are the names of the currents that you will be following? Given that Tori spent 81 days for her trip, how long would you expect your voyage to take? You can just estimate this based on the length of your voyage compared to the distance that Tori traveled (may help to draw Tori’s route on your map and then just compare the distances).