Mapping and the shape of the earth's surface

A. Terms that should mean something to you
Related words are grouped together

Sealevel Surface relief Topography Morphology	Elevation Map Topographic map Bathymetry Chart Bathymetric map	Sonar Side scan sonar Acoustic wave Two-way    travel time Echo-sounding Multibeam mapping Swath	Global positioning    satellites (GPS) Geographic    information    systems (GIS)
Topographic map Bathymetric map Elevation/    bathymetric contours Color contours Data visualization	Satellite altimetry Geoid vs. spheroid Gravitational field	Gridded location    systems Latitude    Equator    Parallels    North star Longitude    Prime meridian    Greenwich    Prime meridian    Chronometer    International    Date Line

B. Questions you should be able to answer
1. How do we know the shape of the seafloor?
2. How do you measure depth using sonar?
3. Why is multibeam mapping an improvement over sonar?
4. How do you measure depth using satellite altimetry?
5. What are the advantages of each: multibeam vs. satellite altimetry?
6. Why are maps from the 1700's not very realistic looking?
7. How can you determine latitude if you don't have GPS?
8. How can you determine longitude if you don't have GPS?

C. On the web - General references

Coasts in Crisis
Basic information about coasts.
Williams, Dodd, and Gohn, U.S. Geological Survey

View Above Earth
Type in any latitude and longitude and see a view of the Earth over that spot.
Fourmilab

Side Scan Sonar
ABC

Satellite altimetry
Mapping seafloor bathymetry by measuring the elevation of sealevel.
Maps
NOAA

TOPEX/Poseidon
Satellite that measures global sea level and allows us to map currents and bathymetry.
NASA

Basics of Space Flight
Measurements of global sea level from which we can derive currents and bathymetry.
Jet Propulsion Laboratory, NASA/CalTech

J-Pass
Find out when satellites will be passing overhead and look for them at night.
NASA

GPS - A New Constallation
Find out more about this tool that's being used for everyday business.
National Air and Space Museum

John Harrison and the Longitude Problem
How a working class joiner from Lincolnshire with little formal education takes on the scientific and academic establishment of his time and wins the longitude prize through sheer determination and an extraordinary talent and technical insight, making a major step in modern global navigation systems.
Royal Observatory Greenwich

D. On the web - Current topics
1.    Elevation of Mt. Everest
2.    U.S. coastal multibeam maps

E. Notes and diagrams
1.    Shape of the seafloor
2.    Latitude and longitude
3.    Using the North Star to determine latitude
4.    World Time Zone Map