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Daily Updates: March 2000
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Daily Updates: April 2000
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Daily Updates: May 2000
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partly cloudy weather

Partly Cloudy
84.2°F (29°C)
Latitude: 3 deg 7.8’N
Longitude: 102 deg 12.7’W
Wind Direction: NE
Wind Speed: 8 Knots
Sea State: 0
Swell(s) Height: 3-5 Foot
Sea Temperature: 84°F (28.9°C)
Barometric Pressure: 1012 MB
Visibility: 10-25 Nautical Miles

what's to eat today?
Corned beef hash and poached eggs
Creamed chip beef
Blueberry pancakes
Cinnamon rolls
Cottage potatoes and toast
Bacon and sausages
Hot and dry cereal
Assorted tropical fruits

Stuffed pork chops
Mashed potatoes with gravy
Pepper pot soup
Cheese Ravioli
Shrimp salad
Cheese and Salami tray
Salad bar
Homemade peanut brittle

Teriyaki tenderloin
King crab legs
Rice and zucchini
Fresh bread
Salad Bar
Banana cream parfait

Last night, Dave Grimes and Dave Murline caught some enormous squid. They were bigger than the ones you usually see either in aquariums or on your dinner plate when you have calamari, the Italian name for squid. These squid will show up on our dinner plates in the next few days as delicious entrees. One benefit of being out at sea is getting fresh seafood almost any time. The “Daves“ are keeping us well stocked!


Using sonar to create seafloor images
April 2, 2000
By Dr. Dan Fornari

The sun rose hot and bright this morning over a sparkling blue sea. It was another beautiful day in the tropics, but you couldn’t tell if you were on duty inside the Control Van and paying close attention to operating and monitoring the DSL-120 sonar fish. The windowless van is usually kept dark so that people can see the TV and computer monitors better. After a four-hour watch, you walk outside and feel what a mole must feel like coming out of its hole-dazed and shocked at how bright the sun is.

We are continuing to tow the DSL-120 sonar fish north and south along the crest of the East Pacific Rise near 3° 20’N latitude. We are flying the fish over a zone where the AHA hydrophones indicated that earthquakes occurred four years ago. We are searching for evidence of that seafloor volcanic eruptions took place here. We are also busy making maps of the seafloor and we will post a few of them on the Web in the coming days to give you a picture of what the seafloor looks like where we are working. We don’t have maps right away because we are not taking photos of the seafloor. We are bouncing sound waves off the seafloor and then “processing” this data to make an image. In a way, we are translating sound into a picture. Many techniques are used to process the many different types of data we collect, and many people on board specialize in this work. Uta Peckman of Scripps specializes in processing multibeam sonar data. Steve Gegg is the expert data processor of the Woods Hole Deep Submergence Operations Group on board. Tom Crook, also part of the Woods Hole team, is the expert navigation data processor. Rob Palomares of Scripps is the expert processor of CTD data (conductivity, temperature and depths of water). Dan Scheirer, Paul Johnson, Gregg Kurras, Julia Getsiv and Scott White are all scientists working on processing the different data we are collecting during this expedition.

Over the past week, we have sent back a lot of information about what we are doing on board RV Melville. The students on board and I thought it might be fun for you to try a “Sea Quiz” that we put together.

Dive and Discover
“Sea Quiz #1”

1. The East Pacific Rise is:
a) the name of a mountain range in South America.
b) located in the North Atlantic Ocean.
c) a mid-ocean ridge spreading center in the eastern Pacific Ocean.
d) a transform fault.

2. A multibeam sonar is:
a) a navigation device that gives latitude and longitude of a ship.
b) a sonar that emits a single ping of sound to determine seafloor depth.
c) an instrument to listen to music.
d) a sonar mounted on the hull of a research ship that emits many pings of sound to produce data to make seafloor maps.

3. The mid-ocean ridge is:
a) a plate boundary where Earth’s ocean crust is formed.
b) a mountain range in Asia.
c) a line of volcanoes in the middle of a plate, like the Hawaiian Islands.
d) a transform fault.

4. Global Positioning System (GPS) navigation uses:
a) transponders to determine latitude and longitude.
b) several satellites that help determine the accurate geographic location of ships, planes, cars and people on Earth’s surface.
c) telephones to communicate between ships at sea.
d) sound waves to determine seafloor depths.

[Click here to see your answers].