Oceanic Observations and World Ocean Orgins Ch.1

Question 1

what percentage or earth’s suface is covered by oceans?

Answer 1

70.8%

Question 2

CTD (conductivity-temperature-depth)

Answer 2

• main instrument in oceanography

- measures temp and salinity

Question 3

The Rosette (w/ CTD+ more sensors+ water sampling)

Answer 3

• deployed off ship usually
• data fed back to ship along wire in realtime
• Naskin bottles sample ocean water at selected depths

Question 4

ARGO Floats

Answer 4

A CTD that drifts with ocean currents and comes to the surface regularly to communicate with satellites and transmit data

Question 5

acoustic doppler current profiler (ADCP)

Answer 5

measure velocity in oceanb by pinging sound waves and analyzing the return wave

Question 6

Air-sea interaction meteorology

Answer 6

measure ocean T and S, atomsphdric wind, pressure, radiation nad precipitation; usually on oceanic buoys or research ships but also on land or on sea ice

Question 7

Nebular hypothesis

Answer 7

all bodies in the solar system formed from Nebula

• Gravity concentrates material at center of clouds (sun)
• protoplanets form from smaller concentrations of matter (eddies)

Question 8

Proto-earth

Answer 8

• larger than earth today
• homogenous composistion
• H/He atmosphere
• bombarded by meteorites
• moon formed from collision with an Mars-sized asteroid
• desnity stratification

Question 9

Lithosphere

Answer 9

-cool rigid shell
-includes crust and upper mantle
-about 100km thick
forms tectonic plates

Question 10

orgin of earht’s atmosphere

Answer 10

• initially mostly H and He that was blown out to space by the solar wind-
• outgassing;occured during drnsidsty stratification as earth colled ; water vapour, carbon dioxide, hydrogen, other gases ALMOST NO OXYGEN

Question 11

orgin of earth’s oceans

Answer 11

• outgassed water vapour fell as rain
• the first pernament oceans formed about 4 billion years ago
• salinity developed from dissolved rock elements

Question 12

how do we kow the age of earthn

Answer 12

radiometric age dating using isotopes

-earth is about 4.6 billion years old

Question 13

Archean earth System

Answer 13

• 3.8 to 2.5 billion years ago (Ga)
• atmosphere had hardly any oxygen; eeriest life probably anaerobic
• UV radiation (no ozone shield); earlist life proabaly underwater

Question 14

First Autotrophs (Autotroph ia an organism that can produce its own food0

Answer 14

• similar to anaerobic bacteria; survive without O2

- Chermosynthesis; photosynthesis had not evolved

Question 15

stomatolites

Answer 15

biofilms of cyanobacteria capture and bind sediment

Question 16

kerogen

Answer 16

• concentrated, high-molecular-weight organic compounds occuring in sedimentary rocks
• precursor to fossil fuels

Question 17

carbonate (most commonly CaCo3)

Answer 17

• the mineral in limestone

- many marine animals form carbonate shells