Oceans, Water on Earth, Seafloor, and Bathymetry

size/shape/rotation of Earth is fundamental to ocean dynamics

- interesting to know history of Earth’s geometry

- dimensions of ocean basins important to their oceanography

- distribution of land is important as well

- need to know about water, of course!

Geography 104 - “Physical Geography of the World’s Oceans”

world map 450 BC – Herodotus (484-425 BC)

Johannes Schöner (1477-1547)German globe maker; map circa 1520

world’s oceans

Southern Ocean officially adopted in 2000 by the International Hydrographic Organization

~155x106 km2

~14x106 km2

~68x106 km2

~76x106 km2

~20x106 km2

http://www.cerfacs.fr/globc/links/pictures/southocean.html

Southern Ocean

http://fstec.fjkjt.gov.cn/worldmap/norm_htm/southocean.htm

Including “marginal seas”

Arctic Ocean Southern Oceansurrounded by Eurasia and North America encircles the Antarctic warm ocean moderates frigid land icy landmass feeds cold oceanfresh rivers feed the Arctic Ocean melting glaciers feed the SO ice forms at center of the Arctic ice forms along coastlinesea ice decrease fast sea ice decrease slow

percentage of land and water in each 10° latitude band

ocean volumes and areas

Very confusing

formal introduction to the Earth’s geometry and maps

next up: water on Earth, seafloor, bathymetry

then finally: oceanography!

atmosphere ~0.001%rivers/lakes ~0.04%groundwater ~0.36%

glaciers/land ice ~1.6%

oceans/sea ice ~97.9%

Source: Gleick, P. H., 1996: Water resources. In Encyclopedia of Climate and Weather, ed. by S. H. Schneider, Oxford University Press, New York.

where’s the water on Earth?

hypsographic curve

coastal settlement and sea level

sea level stabilization

“urban transition”

Figures from Eos research article.

“we hypothesize that…”

sea level rise and human populations

6 m sea level rise

Santa Barbara and sea level rise

IPCC [2007]

Global ClimateChange

Sea level rise 1870 to 2007 = ~20 cm (~8 inches)

ΔT 1860 to 2007 = ~0.8 C (~1.25 F)

IPCC reports: 1990, 1995, 2001, 2007

Readings for next time (Seafloor):

Read Chapter 4 “Seafloor Features”; article “Emergence of Complex Societies After Sea Level Stabilized”; article “Risk of Rising Sea Level to Population and Land Area”