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Journals 2007/2008

Kimberly Pratt
Alvarado Elementary School, Union City, California

"Atlantic Northeast Shelf Ecosystem Monitoring Project
NOAA, R/V Delaware II
August 15 - 29, 2007
Journal Index:
August 15 - 16 - 17 - 18 - 19 - 20 - 21 - 22
           23 - 24 - 25 - 26 - 27 - 28 - 29


Additional Resources

August 26, 2007
Dropping Cups

Latitude: 42° 15.94' N
Longitude: 66° 04.06' W
Sea Depth: 257.4 m
Wind Speed: 10.1 kts
Sea Temp: 15.4
Location: 180 miles off of Cape Cod, MA
Time: 1730

Today was a good day! Waking up to another foggy day is very comforting - the fog softens the ocean and it is really beautiful. When the days are foggy, it really makes you long to be in your berth, reading and sleeping. The berths are very comfortable, and the sea will literally rock you to sleep. Today, we dropped the Styrofoam cups that had been decorated by students in Union City into the ocean. We dropped them at three different depths. The first was on the ocean floor, the next 100 meters off the bottom and the last was 30 meters from the 100 meter depth. We wanted to see the difference in sizes according to pressure at different depths. As you can see there is a difference. The reason is every 33 feet of seawater provides 2 atmospheres of pressure - one for the air and one for the water. For every 33 feet of depth another atmosphere is reached. It measures 15 pounds for every 33 feet. The pressure changes not linear, but logarithmic. So the deeper the cups go, the more pressure is added to squeeze the air out of the cups, shrinking them. It really demonstrates the effects of pressure. Just think about how the animals in the ocean handle the pressure. Especially when you think that sperm whales dive to hundreds of meters of depth without being crushed. Amazing. Today we continued sampling, and I collected a small shrimp in the net to take home. The trip is going by very quickly now. On Wednesday, we will be back in Woods Hole - time flies when you are having fun!