Life at vents & Marine Mining HW 2C+ 3A

C. How will this mining be carried out? (what equipment will be used)

A support vessel, auxilary miner as a giant mill to grind rock, and a gathering machine to pump rock slurry to surface.

1. A. What are Back-arc basins?

Back-arc basins are back-arc seafloor spreading (associated with subduction zones) and metal sulfide deposits.

1. What is the base of the food chain at hydrothermal vents on mid-ocean ridges? How could this be considered an ocean "resource"?

Chemosynthetic Bacteria is the base of the food chain. Oxidation of H2S. It is considered an ocean "resource" because it is an analogue for early life on earth and we can get enzymes for medicine from it.

C. Are these types of back-arc basin metal sulfide deposit a resource anywhere else? What metals are sought and where do these occur (name a country/countries or region)

High gold and copper content in Ontario, Canada.

4. What are some potential problems with:A. the technology and physical process of mining the seafloor, and

Humans have no done it yet and we do not have enough experience to ensure we successful mine the seafloor accurately without damaging the environment.

3. What is present at the bottom of the Red Sea (page 91)? How and why does this deposit differ from metal deposits at mid-ocean ridges out in the open-ocean? Who is interested in mining metal deposits in the Red Sea, and why?

Metal-rich sediments/ Sulphide-rich sediments. These deposits differ from metal deposits at mid-ocean ridges because it runs exactly along the middle of the Red Sea. Saudi Arabia and Sudan are interested in mining metal deposits in the Red Sea because it contains an abundance of zinc, copper, silver, and gold -closed basin with dense brines- retains all metals- huge ore deposit

2. A. Where is it currently planned to mine massive sulfide deposits at an oceanic spreading center (in a back-arc basin)?

Papa, New Guinea.

B. How do metal sulfide deposits at back-arc spreading ridges differ from those at mid-ocean ridges? (What metals are present in higher concentrations than in deposits at mid-ocean ridges to make these deposits more valuable?)

Rocks in back-arc spreading ridges are more meta-rich and contains higher concentration of Gold. while exposed on land

B. the seafloor and oceanic environment resulting from seafloor mining?

Seafloor Mining will create acid with toxic metals and grind up animals while endemic species could also be affected.

2. What are some other organisms at hydrothermal vents? How are these related to bacteria?

Shrimp, crab, tubeworms, clams. The tubeworms and clams have a symbiotic relationship with bacteria. Shrimp and Crab eat bacteria

3. Besides hydrothermal vents, where else on mid-ocean ridges does microbial life (bacteria) occur?

Subsurface biosphere. (older crust, lower temperature) Also at Mid-ocean ridges- seawater flows through cracks and pores-> support Bacteria life.

B. What are some features that make this specific site a good one for seafloor mining?

The site has high Gold and Copper content, also has zinc and lead. It has 2 million tons of content while it's only 2-3 km deep. close to land with one processing facility