Flashcards
Will lecture 1
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- 1Ocean and Seafloor: =depth can alter habitat structure =hadal zone has earthquakes through seismic waves - not area above =e.quakes can alter the habitatSounding = recording the depth of a body of water
-deep sounding started in 1733 - difficult due to sheer depth of ocean
-John Murray began to map ocean floor
-key finding = ocean floor is very uneven - 2Mapping: -seismic bombing used initially along with weighted lines modern mapping = swath bathymetry, satellite data, real life mappingPlate Tectonics:
Alfred Wegener- Pangaea - continents used to join to create one large land mass
Mid ocean Ridges = spreading centres - new crust formed by magma rising out of surface
Plate tectonics accepted - 1965 - 3Zones: Divergent = away from each other -seafloor spreading Convergent = towards each other- subduction Transform = side-by-side 15 tectonic plates knowntrench formation = during collision, heavier oceanic crust is pushed under, lighter continental crust rise up creating island arc
Ridge formation - new seafloor - from diverging plates - 4Oceanic depth: Challenger II - 10860m in 1951 using baillie rod JAMSTEC - 10971m - million dollar project by Japan for extra 100m -oldest crust in western Pacific -crust can provide info on past climate etcDeepest trenches:
-all in Pacific-
1. Mariana Trench
2. Philippine Trench
3.Kuril-Kamchakta Trench
4.Kermadec Trench
5.Tonga Trench
all above 10000m - 5-at 6000-6500m there is abrupt distinction in fauna, above this there is succession Trench = deep single elongated area deeper than 6500m - generally formed by subduction or fault Trough = large area or cluster of basins deeper than 6500m - not formed at converging boundaries but plates with abyssal plainshadal zone only counts for 0.24% of entire ocean but 41% of total death range of ocean
trenches create multiple habitats - no two trenches the same
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- Flashcards on Will lecture 1, created by Laura Murray on 24/05/2019.
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- Laura Murray · May 2019
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- May 27, 2019
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