Exam 3 Flashcards
Where is most freshwater?
glaciers, ice caps, underground aquifers
How much of Earth’s water is easily accessible to humans?
1 part in 10,000
What is 1/5th of Earth’s fresh water supply?
groundwater
How much of fresh water is surface water?
1%
What is the composition of ocean water?
96.5% H2O by mass, otherwise mostly salts
How much salt would here be if all water were evaporated from the oceans?
63-meter-thick layer
What is the longest mountain range in the world?
Mid-Atlantic Ridge (under the Atlantic ocean)
What could result from the slowing of thermohaline circulation?
Greenland would melt, giving the Atlantic less dense fresh water, and cooling Europe
El Niño
air pressure in the eastern Pacific decreases and in the western Pacific increases, weakening equatorial winds and sending warm water toward South America, suppressing upwelling along the Pacific Coast of the Americas, and shutting down a delivery of nutrients
How frequent are ENSO cycles?
every 2 to 8 years, though they may be increasing in frequency with climate change
What affects salinity in estuaries?
daily or seasonal variations in tides, fresh water runoff
How many people live within 160 k of the ocean?
2/3
What do mangroves help with?
protect shorelines from storm surges, filter pollutants, capture eroded soils to protect coral reefs
How many mangrove forests have been destroyed for development?
1/2
How tall and how much can kelp grow?
60 m tall, 45 cm per day
What do kelp forests help with?
shelter/food for invertebrates/fish, absorb wave energy to protect shorelines from erosion
Reef
underwater outcrop of rock/sand/other material
Corals
invertebrates related to sea anemones and jellyfish that remain attached to rocks/existing reefs to capture food with stinging tentacles or eat zooxanthellae
Zooxanthellae
make coral reefs colorful
What do coral reefs help with?
absorb wave energy to protect shorelines, host biodiversity (regions of high primary productivity)
What causes coral bleaching?
zooxanthellae die due to rising temperatures or more pollutants, depriving coral of nutrition
How much solar energy do the uppermost 10 ft of ocean absorb?
80% that reaches the surface
Where do ocean surface primary production and animal life concentrate?
areas of nutrient-rich upwelling
Detail the pelagic food chain
plankton at the base, then zooplankton, then fish/jellyfish/whales/free-swimming animals