eesc 2200 the solid earth system

EESC 2200The Solid Earth System

Bill Menke

Geophysicist

Terry Plank

Geochemist

Survey

Your major? DEES/Env DEES/Earth DE3B 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 discussionsCase 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’sLisa 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 ReadingsEarth: 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 GlobeYou will need an inflatable globe

Available from the Department for a small fee

See the TA’s

Globe needed for first two labs

Owing to the large class size, we will be hold two trips, one on

Saturday October 18, 2008And the other on

Sunday October 19, 2008You may opt to write a term paper in lieu of attending the fieldtrip

Required full-day fieldtripRequired full-day 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 % Homework25 % Lab Report

25 % Midterm25% Final

-15% miss fieldtrip and no term paper

we almost never violate class rank inassigning 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 EESC2100 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 EESC2300 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 aGlobal Topographic Dataset

This data viewer is at http://ingrid.ldgo.columbia.edu/SOURCES/.WORLDBATH/.bath/html+viewer?

Continents …. And …. Oceans

Viewer can makea topographicprofile

sea level

Is this the kind of profilethat 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 betweencontinent and ocean …

sea level

Very sharp change in topography …

Idealization: world has two levelscontinental level and ocean level …

continental level

Doesn’t work everywhere … e.g. Andes Mountains

ocean level

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 …