EESC 2200 The Solid Earth System Bill Menke

EESC 2200 The Solid Earth System Bill Menke Terry Plank Geophysicist Geochemist

Survey Your major? DEES/Env DEES/Earth DE 3 B DEEE BCES Other Have you taken? 2100 -Climate 2300 -Life Summer activities team sports hiking boating science-related internships

Course Format

Monday 2: 40 -3: 55 Monday meetings will always be a formal lecture But note. . . questions and discussion are always encouraged

Wednesday 2: 40 -3: 55 Wednesday meetings will not always be a formal lecture We will also have Class discussions Case Studies Projects and Tutorials

Monday 4: 05 -7: 00 Our second meeting on Monday will be a lab It will be conducted by our two TA’s Lisa Streit and Tianxia Jia Because of the large class size this year, we will break it into two sessions 4: 05 -5: 30 and 5: 35 -7: 00 Lab Reports are required

Text and Required Readings Earth: Portrait of a Planet, Third Edition by Stephen Marshak; Publisher: Norton, W. W. & Company, Inc. ISBN-13: 9780393930368 Available at Barnes & Noble Required readings will be posted on Courseworks (This week – Chapters 1 & 2 )

Inflatable Globe You will need an inflatable globe Available from the Department for a small fee See the TA’s Globe needed for first two labs

Required full-day fieldtrip Owing to the large class size, we will be hold two trips, one on Saturday October 18, 2008 And the other on Sunday October 19, 2008 You may opt to write a term paper in lieu of attending the fieldtrip

Homework will be assigned periodically you will be given at least 1 week to complete each assignment they will be due in hardcopy at the start of a designated class (no homework has yet been assigned)

Grading 25 % Homework 25 % Lab Report 25 % Midterm 25% Final -15% miss fieldtrip and no term paper we almost never violate class rank in assigning grades Bill & Terry have a written grading policy: www. ldeo. columbia. edu/users/menke/gradingpolicy. html

Today’s Discussion: The significance of Continents and Oceans

Although this is a course mainly about the physical aspects of the earth, let’s start with a social question … What significance have "continents" and "oceans" had for human history

Let’s move onto a question concerning climate … (how many of you have taken EESC 2100 The Climate System)? What significance have "continents" and "oceans" had for climate

Let’s move onto a question concerning biology … (how many of you have taken EESC 2300 The Life System)? What significance have "continents" and "oceans" had for the development of life on earth?

The surface of the earth can be divided into oceans and continents. Do they have significance beyond the obvious fact that one is wet and the other dry, one is low and the other is high?

Let’s examine a Global Topographic Dataset This data viewer is at http: //ingrid. ldgo. columbia. edu/SOURCES/. WORLDBATH/. bath/html+viewer?

Continents …. And …. Oceans

Viewer can make a topographic profile sea level

Is this the kind of profile that you would get by pouring water on any-old irregular surface ?

Pour in a little water … a little ocean …

Pour in a lot of water … a big ocean …

(demo here …)

Examine the boundary between continent and ocean … sea level Very sharp change in topography …

Idealization: world has two levels continental level and ocean level … continental level ocean level Doesn’t work everywhere … e. g. Andes Mountains

How would you test this idea of two levels ?

Make a histogram of global evevations

Topography at 9500 random points around the globe. Why is the density of points greatest at the equator?

Histogram of elevations Narrow range of continental levels Most data between -150 meters to 1500 meters Somewhat less narrow range of ocean levels Most data between -5000 meters to -3000 meters

The earth colored to bring out the geographic distribution of these two levels

But what does it mean? What are the right questions?

Why are there just two levels? (why not 3? ) Why is the boundary between the two levels so sharp? What controls the depth of each level? Why is the top level close to – but not exactly at - sea level? Does water level control continental level; does continental level control sea level?

What approaches might allow us to answer these questions?

A planetary science approach (fun, but dreadfully expensive …)

Only our earth has two distinct levels …