UWHS Oceanography: Focus on Washington Waters

Lynne Buechler

Geography & Navigation

Geography: Shape of the EarthEarth not quite a

sphere creates a slight equatorial bulgePolar radius=6365

kmEquatorial

radius=6387 kmDifference is 22 km

or 13 mi!

http://www.see.leeds.ac.uk/structure/dynamicearth/internal/shape.htm

Geography: Shape of the EarthDistribution of continental

mass at mid latitude in the N. HemisphereSlight depression w/ an

elevation at the N. PoleAntarctica centered on the

S. Pole in the S. Hemisphere Inflated bottom half

This “pear” shape is actually a small effect and the Earth is fairly spherical

http://www.jpl.nasa.gov/news/news.cfm?release=2002-217

http://www.lead.org.au/bblp/Climate_Change/sld002.htm

Geography: Earth the Water PlanetOcean Planet

Oceans cover 140 million mi2 of earth’s surface71% of Earth’s

surface is covered by water

Total volume=1.35 billion km3

Physiographic MapsGraphic representations of major features

Navigation: Charts & MapsLab 1

Bathymetric ChartsAccurately reflect the topography of the ocean

floor by providing contour intervals of constant depth

Navigation: Charts & Maps

http://frank.mtsu.edu/~cdharris/honors/island-maps/Sigsbee-Plain.htm

oceanexplorer.noaa.gov

Navigational ChartsType of navigational chart with more

navigational aids: Signals> lighthouses, buoysLandmarksDangers> rocks, underwater cables, kelp beds, etc. Bottom Characteristics>

Rocks, sediment type, etc.

Navigation: Charts & Maps

http://www.dreamstime.com/stock-photo-nautical-navigation-chart-tools-image11097000

Datum= the “zero” level to which elevation and depth are referenced or sea level usually.

Sea level fluctuates with tidal movement Depth to seafloor= MLLW or “mean lower low

water” a tidal descriptive term is usedLand elevation=MHW or “mean high water” is

used

Navigation: Elevation & Depth

Geography: Latitude and Longitude

W E

Prim

e M

erid

ianEquator

N

S

Geography: Where are you?Where is the approximate

latitude of Covington? 122° 6' 49" W “Parallels” 1⁰ Lat.=111.32 km=60

Nautical MilesLongitude?

To the nearest second? 47⁰ 20’53”=47 degrees,

20hours, 53 minutes

Geography: What is the Puget Sound?Sound? Fjord? Estuary?Sound: complex of inland

waterwaysFjord: system of flooded

glacial valleysEstuary: semi-enclosed

coastal (salty water) body of water with one or more rivers or streams flowing into it

Mikelle Nuelle, professor of Oceanography UW

Richard Strickland, Professor of Oceanography UW

Sverdrup & Armbrust, Introduction to the World’s Ocean’s Ch 2

Sources