Oceans ~ Continued Messana
Ocean Waters Contains NaCl, dissolved solids & gases (O2, N2, CO2) Salinity = 35g salt/1000g seawater Higher salinity = higher density of water Objects are more buoyant in water that is more dense (Dead Sea – 10X saltier than ocean- >more dense ->humans more buoyant)
Buoyant Force vs. Gravity
3 Layers of Ocean 1. Surface = warm water, less dense, coldest at poles, warmest at equator, 0- 300 m, 25 C 2. Thermocline = temperature drops fast as depth increases, 300 – 700 m, 25->5 C 3. Deep = cold all year, barely above freezing, 0-3 C
Ocean Currents Currents = mass of moving water, distributes heat & nutrients Surface Currents – caused by WINDS Top 200 meters Rotate different directions in each hemisphere Pull warm water from equator & cold water from poles Gulf Stream = surface current that moves water from the Gulf across Atlantic Ocean, northeastward toward Britain, makes climate there more mild El Nino = change in surface currents in Pacific due to winds not blowing as strongly west across the Pacific, affects weather patterns globally
Surface Currents surrounding US
Ocean Currents Deep Currents – caused by DIFFERENCES IN DENSITY (due to temperature & salinity) 1. Upwelling: movement of water up to surface, brings up nutrients, good for animal life 2. Downwelling: movement of water from surface to greater depths, carries O2 down, allows for life
Upwelling & Downwelling
Exploring the Ocean Floor How can we overcome ocean obstacles to learn more?... Pressure Darkness Lack of air Cold Wildlife
Exploring the Ocean Floor Technology to use: Submarines Submersibles (Alvin) Robots with cameras Sonar = using sound waves to measure distances, depths, locate objects Satellite Imagery – light waves from space
University of Miami Submersible
The Ocean Pearl
Sonar for measuring depth of ocean floor: