Hyrdrological cycle

how was water delivered to the earth?

formed through meoteorites and comets, water came from the core of the earth to the surface and conditions on earth needed to be just right to store it

what help’s support the holding of liquid water?

the perfect albedo at earths surface

what bonds does water have?

polar molecule that is covalently bonded with intermolecular hydrogen bonds

what are the main properties of water?

high boiling point and heat capacity, present as liquid,gas and solid on earth, very good solvent, density decreases when frozen

what percent of earth’s water is freshwater?

2.5%

what are the main pressures on freshwater resources?

over-extraction for agriculture, pollution, impacts of climate change, growing demand

what are some methods for sustainable management?

water conservation, protecting freshwater ecosystems, improvements in water infrastructure

where does evaporation mainly occur?

equatorial ocean regions

how is glacial rock flour formed?

glaciers continually rub over base rocks creating very fine particles creating the glacial rock flour

what is chemical weathering?

chemical weathering dissolves rock and transports its chemical constituents to the oceans in dissolved forms

what is the process of chemical weathering?

• co2 dissolves in rainwater and reacts to form carbonic acid

• this falls on the land interacting with carbonate rocks creating hydrogen carbonate which runs into the ocean

why is chemical weathering considered negative feedback?

• warm high co2 levels accelerates chemical weathering

• lowers CO2 which hinders weathering allowing CO2 to build up again

• this regulates levels of atmospheric CO2

when was the Paleocene-eocene maximum?

56 million years ago

what was the Paleocene-eocene maximum?

massive release of CO2 triggered 5 to 8 degrees of global warming however increased weathering meant it eventually returned to normal