BrainScapeDeck_EAE3311_1_20210309_132647

Question 1

<p><strong><span>What are the 3 Bathymetric Provinces?</span></strong></p>

<p>3 points.</p>

Answer 1

<ul> <li>Continental margins (22% of ocean area)</li> <li>Deep ocean basins (42% of area)</li> <li>Mid-ocean ridges (31% of area)</li></ul>

<p><span>_{EAE3311 1aa}</span></p>

Question 2

<p><span>Describe</span></p>

<p><strong><span>Abyssal Plain</span></strong></p>

<p>5 points.</p>

Answer 2

<ul> <li>Depositional surface (wind and volcanic, shells)</li> <li>Deep cold and dark and generally flat (but seamounts)</li> <li>Fine sediments (ooze), brown-red clays</li> <li>Undisturbed (excellent for palaeoreconstruction)</li> <li>Some turbidites (depending on input and trenches)</li></ul>

<p><span>_{EAE3311 1ab}</span></p>

Question 3

<p><strong><span>What are the sizes of Australia's environments?</span></strong></p>

Answer 3

<div>Australia’s deep-sea environment (8.2 million km²) is larger than the landmass of Australia (7.7 m km²)</div>

<div></div>

<p><span>_{EAE3311 1ac}</span></p>

Question 4

<p><strong><span>What are Guyots?</span></strong></p>

Answer 4

<p><span>Magma incursion</span></p>

<div>Pronunciation = ‘Goo-Yots’</div>

<p><span>_{EAE3311 1ad}</span></p>

Question 5

<p><strong><span>Key features of Deep Ocean Basins</span></strong></p>

<p>3 points.</p>

Answer 5

<ul> <li>Abysall hills</li> <li>Seamounts</li> <li>Guyots</li></ul>

<p><span>_{EAE3311 1ae}</span></p>

Question 6

<p><strong><span>What are the descriptors of the Abyssal Plain</span></strong></p>

<p>5 points.</p>

Answer 6

<ul> <li>Abysall Hills <500 m relief above sea floor</li> <li>Knolls <1000 m</li> <li>Seamounts - >1,000m (conical)</li> <li>Ridges (length/width ratio >2)</li> <li>Guyots (flat topped)</li></ul>

<p><span>_{EAE3311 1af}</span></p>

Question 7

<p><strong><span>What is the faunal density of seamounts?</span></strong></p>

Answer 7

<div>Seamounts that reach to within 1,500 m of the ocean surface have much higher density of faunal coverage than deeper seamounts. </div>

<div>Faunal density reached 90% coverage at 1,000-1,100 m depth on 13 unfished seamounts surveyed by Williams et al. (2006)</div>

<div>Coverage was less than 10% at 1,400-1,500 m.</div>

<div></div>

<p><span>_{EAE3311 1ag}</span></p>

Question 8

<p><strong><span>How important are Deep Sea Trenches?</span></strong></p>

<p>4 points.</p>

Answer 8

<p><span>Deep sea trenches are 5% of area</span></p>

<ul> <li>Continental margins (22% of ocean area)</li> <li>Deep ocean basins (42% of area)</li> <li>Mid-ocean ridges (31% of area)</li> <li>Deep sea trenches (5% of area)</li></ul>

<p><span>_{EAE3311 1ah}</span></p>

Question 9

<p><strong><span>What is the mid-oceanic ridge system?</span></strong></p>

Answer 9

<p><span>A continuous underwater mountain range that winds through every ocean basin in the world</span></p>

<ul><li>50,000 km long, ~2.5 km high</li><li>Fractured looking</li><li>Entirely volcanic</li></ul>

<p><span>_{EAE3311 1ai}</span></p>

Question 10

<p><strong><span>What are the deep ocean trenches?</span></strong></p>

Answer 10

<ul> <li>Trenches, mostly in the Pacific, but found in other oceans too</li> <li>Deepest is the Mariana Trench (11,022 m)</li></ul>

<p><span>_{EAE3311 1aj}</span></p>

Question 11

<p><span>Describe</span></p>

<p><strong><span>Continental Crust</span></strong></p>

<p>4 points.</p>

Answer 11

<ul> <li>Main rock is granite (and andesite)</li> <li>Density = 2.7 g/cm3</li> <li>Average Thickness = 35 km</li> <li>Much Older than Oceanic</li> <li>29% of the Earth’s surface</li></ul>

<p><span>_{EAE3311 1ak}</span></p>

Question 12

<p><span>Describe</span></p>

<p><strong><span>Oceanic Crust</span></strong></p>

Answer 12

<ul> <li>Main rock is basalt (and gabbro)</li> <li>Density = 3 g/cm3</li> <li>Average Thickness = 8 km</li> <li>Much younger than Continental</li> <li>71% of the Earth’s surface</li></ul>

<p><span>_{EAE3311 1al}</span></p>

Question 13

<p><strong><span>What is Isostatic adjustment?</span></strong></p>

Answer 13

<p><span>The vertical movement of the crust</span></p>

<div>Both continental and oceanic crusts float on the mantle beneath</div>

<div>Oceanic crust floats lower (denser) and is also thinner, allowing oceans to occupy it.</div>

<div></div>

<p><span>_{EAE3311 1am}</span></p>

Question 14

<p><strong><span>What are the relative ages of Oceanic & Continental crust?</span></strong></p>

Answer 14

<div>Oceanic crust is very young (<200 <strong>m</strong>ya) </div>

<div>Continental crust is much older (>4 <strong>b</strong>ya)</div>

<p><span>_{EAE3311 1an}</span></p>

Question 15

<p><strong><span>What are the features of the mid-ocean ridge?</span></strong></p>

<div>4 points.</div>

Answer 15

<ul> <li>Basaltic lava (entirely volcanic)</li> <li>A rift valley along the crest</li> <li>Transform faults</li> <li>Hydrothermal vents</li></ul>

<p><span>_{EAE3311 1ao}</span></p>

Question 16

<p><strong><span>What are the types of Hydrothermal Vents?</span></strong></p>

<p>3 points.</p>

Answer 16

<ul> <li>Black smokers >350 deg</li> <li>White smokers 30-350 deg</li> <li>Warm-water vents <30 deg</li></ul>

<p><span>_{EAE3311 1ap}</span></p>

Question 17

<p><strong><span>What do the black smokers precipitate?</span></strong></p>

Answer 17

<p><span>Black smokers have precipitates of metal sulphide</span></p>

(dissolved by the hot water)<p style="text-align:right;"><span>_{EAE3311 1aq}</span></p>

Question 18

<p><strong><span>What do the white smokers precipitate?</span></strong></p>

Answer 18

<p><span>White smokers: precipitates of sulphates of barium and calcium and silica.</span></p>

<p><span>_{EAE3311 1ar}</span></p>

Question 19

<p><strong><span>What are the feature of Hydrothermal Vents?</span></strong></p>

<p>3 points.</p>

Answer 19

<ul> <li>pH<3</li> <li>Unique biological communities based on chemosynthesis (Riftia pachyptila)</li> <li>Short life spans (</li></ul>

<div></div>

<div>CO₂ + O₂ + 4H₂S → CH₂O + 4S + 3H₂O</div>

<p><span>_{EAE3311 1as}</span></p>

Question 20

<p><strong><span>What are the characteristics of the Red Sea?</span></strong></p>

<p>4 points.</p>

Answer 20

<p><span>BABY ocean!<br></br>20 MY old</span></p>

<ul> <li>Deep (1000 m) and narrow axial trough through the centre</li> <li>Basalt (new crust) is injected into the the trough</li> <li>Spreading at a rate of 4 cm/year</li> <li>Deep brine pool highly saline and acidic, commercially viable metal deposits</li></ul>

<p><span>_{EAE3311 1at}</span></p>

Question 21

<p><strong><span>What is the Maritime Zones?</span></strong></p>

Answer 21

<div>TSB = Territorial Sea Baseline</div>

<div>CW = Coastal waters</div>

<div>TS = Territorial Sea</div>

<div>CZ = Contiguous Zone</div>

<div>EEZ = Exclusive economic zone</div>

<div>CS = Continental Shelf</div>

<p><span>_{EAE3311 1au}</span></p>

Question 22

<p><strong><span>What is the imporance of the Australian EEZ</span></strong></p>

Answer 22

<div>Whiin the EEZ, Australia has sovereign rights for the purpose of exploring and exploiting, consrving and managing all natural resources of the waters, seabed and its subsoil.</div>

<div></div>

<div>The EEZ is 200 nautical miles with the exception of some international agreements, e.g. the treaties with East Timor, France, Indonesia, NZ, PNG, Solomon Islands</div>

<p><span>_{EAE3311 1av}</span></p>

Question 23

<p><strong><span>What is key about Australia's EEZ?</span></strong></p>

Answer 23

<p><span>Australia's Exclusive Economic Zone (EEZ) is one of the largest in the world with the total marine area of around 10 million square kilometres which is considerably larger than the 7.69 million square kilometres of the Australian mainland</span></p>

<p><span>_{EAE3311 1aw}</span></p>