Here’s an excerpt from Discovery News about today’s quake.

Sept. 29, 2009 — A powerful earthquake with a magnitude of up to 8.3 struck off the South Pacific island nation of Samoa on Tuesday, triggering a tsunami as coastal residents fled to higher ground.

The Pacific Tsunami Warning Center said waves 1.57 meters (five feet) tall hit American Samoa, while 0.7 meter waves were recorded in Samoa.

The center had earlier issued a tsunami warning for a large swathe of the South Pacific including Fiji, New Zealand and Tonga after the U.S. Geological Survey reported a 7.9 magnitude quake.

The center later said an 8.3 magnitude quake had been recorded at a depth of 33 kilometers (21 miles). It was not immediately clear if this was the same quake and the USGS’s website did not provide exact details of its location.

“Sea level readings indicate a tsunami was generated,” said a statement from the Pacific Tsunami Warning Center.

WATCH VIDEO: Learn more about the Pacific Coast’s tsunami warning system.

Related Content:

• Planet ‘Restlessness’ May Predict Big Quakes
• Triple Junction of Crusts Caused 2007 Quake
• HowStuffWorks.com: Earthquakes
• More Discovery News

About an hour later we were standing on the beach in New Smyrna. Waves were running 5-8 feet and breaking far from the waters edge. A few people played near shore where one minute you were in ankle deep water and the next almost to your waist. The pull of the water as it ran back out to sea was amazing!

Unfortunately later that day the power of the waves took the life of a body surfer in New Smyrna and today waves from the same storm may have claimed more lives in Maine.

One came from the ocean.

Image Credit: Austin Tomlin, Creative Commons

It’s true! Roughly half of the oxygen we breathe is produced by phytoplankton, tiny single-celled plants that live in the sea. That fact alone means that you – and all life on Earth – depend on the ocean for survival every minute of every day. In fact, no matter how far we may live from the coast, the ocean is important to our daily lives in countless ways. The ocean stabilizes our climate and weather patterns and is vital to the global cycle that supplies us with clean drinking water. It provides seafood to millions of people, and studying the wild diversity of life beneath the waves has helped us produce medicines and other important products. For those who live near the water, the ocean offers direct opportunities for employment, transportation, and recreation.

Click here to celebrate Ocean and Water with Year of Science!

I decided to do a quick recap of our discussions about El Nino (actually this includes today and tomorrow). This might help with your notes.

Ocean circulation and how it changes during El Nino. 

• Factors that influence currents: winds, land masses, Coriolis effect
• Normal non-El Nino Pacific currents: strong easterly trade winds, easterly equatorial currents, mounding of warm surface waters in the western Pacific, cold deep water upwelling along South America
• El Nino changes: weak or reversed trade winds, equatorial currents reverse (flow down hill) towards east, central and eastern Pacific warm, western Pacific cools, upwelling ceases.

Relationship between ocean and atmospheric circulation during El Nino:

• Changes in pacific equatorial currents and warming of central and western Pacific affects Walker Cell circulation. Normal Walker Cell circulation collapses and warm moist air raises over the central and eastern Pacific, low pressure moves east.
• Jet streams move south across US
• Changes in these circulations affect the weather around the globe

Weather impacts in Central Florida:

• Changes to jet stream results in fewer hurricanes due to increase wind shear aloft, hurricanes that do form tend to be pushed more towards the north Atlantic.
• Temperatures do not vary significantly, some slight cooling in winter months of about 2-3°
• Increased cloud cover and rainfall, an additional 10 inches (30%). This may have some negative impacts on crops and tourism, however it helps to recharge the aquifers and reduce the number of brush fires
• Increased likelihood of tornadoes

Relationship between ocean circulation, the aquatic food chain and El Nino:

• During non El nino years upwelling occurs along the west coast of south America. This upwelling bring nutrient rich cold bottom waters to the surface where it helps feed small organisms called phytoplankton. Phytoplankton are producers and form the bottom rung of the ocean food chain.
• During El Nino years the upwelling stops which results in significantly less phytoplankton. The reduced levels of phytoplankton means each level higher up on the food chain will have insufficient food.

How El Nino changes might affect the food chain/production in Florida:

• While El Nino has a significant negative affect on the fishing industry along the west coast of South America, it does not have a significant impact on fishing in Florida. El Nino is an event in the Pacific ocean not the Atlantic. However it may affect imports of certain fish and fish products raising prices due to decreased catch
• El Nino does affect our winter crops in Florida with increased rainfall and reduced sun. Increased rain might delay planting or increase diseases. Different varieties may need to be planted or different planting techniques used. El Nino even affects cattle raised in Florida, as pasture area is less productive.

Then we combined ideas from all the classes, asked a few questions of each other to clarify thinking and selected what we (students) thought were the top 5 most significant factors causing water to move through the oceans. Here’s the list (6 listed because of variations between classes):

• Wind
• Temperature
• Earth’s rotation
• Moon’s gravity
• Plate tectonics
• Water Cycle

This is a great list! It shows your ability to apply prior knowledge to new situations, think logically, evaluate various options and engage in debate. I am proud of how well you did.

Lastly you had to do some textbook research into these and present your findings to the class. This had mixed results some very good and others not so good. Textbook research doesn’t seem to be a mastered skill yet, but we’ll work on it. If you were perfect at everything what would you need me for?

Now let’s have some more fun — “scientific messing around”. Let’s play with water!

Looking for some last minute study resources? Then try these classroom PowerPoint presentations:

• Ocean Circulation
• El Nino

 

First you needed to discuss ocean circulation and how it changes during El Nino. Here’s what I was looking for:

• Factors that influence currents: winds, land masses, Coriolis effect
• Normal non-El Nino Pacific currents: strong easterly trade winds, easterly equatorial currents, mounding of warm surface waters in the western Pacific, cold deep water upwelling along South America
• El Nino changes: weak or reversed trade winds, equatorial currents reverse (flow down hill) towards east, central and eastern Pacific warm, western Pacific cools, upwelling ceases.

Second discuss the relationship between ocean and atmospheric circulation during El Nino:

• Changes in pacific equatorial currents and warming of central and western Pacific affects Walker Cell circulation. Normal Walker Cell circulation collapses and warm moist air raises over the central and eastern Pacific, low pressure moves east.
• Jet streams move south across US
• Changes in these circulations affect the weather around the globe

Next discuss the weather impacts in Central Florida:

• Changes to jet stream results in fewer hurricanes due to increase wind shear aloft, hurricanes that do form tend to be pushed more towards the north Atlantic.
• Temperatures do not vary significantly, some slight cooling in winter months of about 2-3°
• Increased cloud cover and rainfall, an additional 10 inches (30%). This may have some negative impacts on crops and tourism, however it helps to recharge the aquifers and reduce the number of brush fires
• Increased likelihood of tornadoes

Discuss the relationship between ocean circulation, the aquatic food chain and El Nino:

• During non El nino years upwelling occurs along the west coast of south America. This upwelling bring nutrient rich cold bottom waters to the surface where it helps feed small organisms called phytoplankton. Phytoplankton are producers and form the bottom rung of the ocean food chain.
• During El Nino years the upwelling stops which results in significantly less phytoplankton. The reduced levels of phytoplankton means each level higher up on the food chain will have insufficient food.

How El Nino changes might affect the food chain/production in Florida:

• While El Nino has a significant negative affect on the fishing industry along the west coast of South America, it does not have a significant impact on fishing in Florida. El Nino is an event in the Pacific ocean not the Atlantic. However it may affect imports of certain fish and fish products raising prices due to decreased catch
• El Nino does affect our winter crops in Florida with increased rainfall and reduced sun. Increased rain might delay planting or increase diseases. Different varieties may need to be planted or different planting techniques used. El Nino even affects cattle raised in Florida, as pasture area is less productive.

A summary recommendation on whether Florida should or shouldn’t hold a conference on the impacts of El Nino:

• Based on our research I would not recommend a conference on EL Nino since the major impacts to Florida are fairly mild except for increased number of tornadoes and some agricultural impacts. However it would seem reasonable to have some type of meeting to discuss tornado preparedness and public safety. Agricultural issues can be resolved through better forecasting of El Nino events allowing farmers to better plan.

Good accurate presentation of this information would have earned a B. To earn an A requires going beyond what we did in class and adding information from additional resources.

1. An Introduction
2. Normal Conditions
3. El Nino Event
   

For a more in depth look go to the Home Study page.

We’ve watched a video, experimented with changing the density of water (by changing the temperature and salinity), tracked floating sneakers, examined wind patterns and their affect on currents, and developed a better understanding of gyres and basic oceanic currents.

I hope the PowerPoint review presentation in class today helped to pull some of these topics together. To develop an even better understanding I’ve put together some additional resources. Remember you can always check out either of our textbooks at the Media Center.

You have online access to the Prentice Hall Earth Science Textbook. Click on the textbook image. The user id is: lms123 and the password is: lakeview. Click on “HS Earth Science -2006″ and the table of contents will appear. Scroll down to Chapter 16 Dynamic Ocean, click on that and review 1. Ocean Circulation. When you are done with that go to Chapter 15 Ocean Water and Ocean Life and review 1. The Composition of Seawater. Be sure when you are using this resource not to change the user profile id or password.

Another resource is Oceans Alive. This site provides a greater variety of information but less detail. It’s a good site to get a bigger picture.

If you’ve been to the Home Study page in the last week or so then you should have noticed the Ocean Currents Online link. This is a much more in depth study, but it provides some audio and video advantages (less reading for you). Click the image to the right to begin this learning guide.