march 28, 2011

March 28, 20111. Finish Our Profiles – Turn In at End

• Finished? Special nautical chart assignment2. Ocean Floor Lab Part II

• I’ll be checking science notebooks while you do lab

3. Homework: Short reading + 3 questions, due next class

Very good in general; we’re almost done There were some things I didn’t explain well:

In general, use same scale on both axes if you want your profile to look “real” – okay this time

I should have added a “cumulative” column to your data sheets to make graphing easier

Make sure to use the same units Remember that your graph is a “profile” or “cross

section” of the path you walked

Profiles

“Cumulative” Column

Measurement Rise Cumulative Rise Run Cumulative Run

1 5.1 5.1 8.7 8.7

2 5.25 5.1 +5.25 = 10.35 10.1 8.7 + 10.1 = 18.8

3 5.1 10.35+5.1 = 15.45 20.5 18.8 + 20.5 = 39.3

Insert columns

Then you can read off the (x,y) pairs to graph:(0,0) (8.7, 5.1) (18.8, 10.35) (39.3, 15.45) etc.

Questions to Answer1. What was the average slope of your profile?2. How does your average slope (answer to #1) compare with

the average slopes of seafloor features shown below?

0.115°

5-25°

0.34°

10-15°5°

30-45°

0°

Do Not Open the Box

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Use a Fine Felt Pen to Mark 15 cm of Skewer (“Depth Sounder”)

Choose Approximately 10 Transects (Lines) to Investigate

10 Lines

Carefully Punch Holes in the Middle of MOST (not all) of the Squares Along Each Line (Transect)

Measure the “Water Depth” and Record the Depth Next to the Hole

15 cm is the top of my skewer

Therefore water depth = 15 – 4.5 = 10.5 cm

4.5 cm leftover

Fold a Sheet of Graph Paper and LABEL it With the Line Name

Record the depth as a Point

10.5 cm

Measure More Depths and Record

Connect the Points

10.5 cm

Ocean Surface

Ocean Floor

Cut Out the Seafloor Shape

Repeat for all Transects (Lines)

• Punch Holes• Sound Depth• Record Depth on Box Lid (ocean surface)• Fold Graph Paper and Label Which Line it is• Mark the Depths on the Graph Paper• Connect the Points• Cut Out Seafloor Shape

Tape or Glue All Transects to Lid

Open the Box

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