Assignment #3: Water Movement (50 pts)
- Global Ocean Currents (17 pts)
Under normal conditions, ocean currents follow very regular patterns. If you were to drop a message in a bottle off the shore of the following locations, where could you likely find it and which current(s) would likely take it there?
- Los Angeles, California
- Florida (Atlantic Coast)
- The Galapagos Islands
- The Seychelles
- The Canary Islands
- The Great Barrier Reef
- Global Wave Patterns (8 pts)
Investigate global ocean wave patterns at http://www.oceanweather.com/data/. Click on the inset map that illustrates the southern California region.
- Describe the size and direction of significant wave height off the southern California coast.
- Go back to the global map and look at the wave height and direction of some other regions. Are there any that currently have an average wave height of more that 30 feet (~9 meters)? Where?
- Why are there much bigger waves in some regions of the planet than others? (In other words, what specific factors cause most of the larger waves to be found in one general region of the ocean?)
III. Modeling Waves (17 pts)
In the open ocean, wave speed (C) is related to the wavelength (L) and wave period (T) by the equation C=L/T. Use this equation to answer the following questions. (In order to convert feet per second into miles per hour, remember that there are 3600 seconds in an hour and 5280 feet in a mile. For example, 100 feet/sec = (100 feet/sec) x (3600 sec/hr) x (1 mile/5280 feet) = 68.18 miles/hr). SHOW YOUR WORK.
- A fierce winter storm blows across a large fetch of the South Pacific near the Antarctic. The waves it generates have a wavelength of 1500 feet with a 15-second period. They originate at a distance of 5000 miles from your favorite Hawaiian surfing beach. How many days will it take for these waves to arrive at your beach (so you know what day to call in sick to work and school)?
- A mild summer storm blows across the North Pacific generating waves with a speed of 10 feet per second. How many days will it take them to arrive at your favorite surfing beach, Huntington Beach, some 1500 miles away?
- A small hurricane whips across the Atlantic with winds of 120 miles per hour. While its fetch isn’t great, it still manages to create a decent swell with a period of 12 seconds and a wavelength of 320 feet. How long will it take in days to reach your favorite surfing beach near Daytona Beach some 600 miles away?
- Using Tide Calendars (8 pts)
Go to the NOAA Tide Prediction Website (http://tidesandcurrents.noaa.gov/tide_predictions.shtml) and navigate to the “Newport Bay Entrance, Corona del Mar, California” link. Use the associated graph and tables to answer the following questions.
Suppose you wanted to do a research project on intertidal animals in Corona Del Mar (Newport Entrance, Corona Del Mar) this semester. Since most of the animals that you want to look at are typically underwater except for at very low tides (below 0), you decide to plan out your research schedule carefully.
- You look at your busy schedule and decide that you can make time in the early morning on either May 11th or May 18th, 2018.
- Which of these dates is preferable? Explain why.
- What exact time is the tide the lowest? How low does it get?
- If you need a tide at or below 0 to get the data you want, about how many hours will you have to work before the tide covers your research site?
- Look at the data/graph that describes the tide on May 17th 2018.
- How high will the tide be at 11:08pm?
- What time of day will have a tide of -1.19?
- What does a negative tide mean? What is this in reference to?
- Suppose you did not have access to a tide calendar and you went outside the night before you were planning on making the trip to your research site to find that the moon was half full. Should you take the time to prepare your research equipment? Explain why or why not.