Earth Science Quiz 3 Q2 Flashcards
Definition of Sea-Floor Spreading
Apparent spreading of the sea floor due to divergence of plates.
Process of Sea-floor spreading:
- Nung nagkaroon ng space, tumaas yung bato galing sa ilalim
- Pagtaas nung bato, bumababa yung pressure causing it to melt and produce magma (decompression melting)
- since nasa ilalim ng water, mas mabilis na lumamig yun forming the new lithosphere/seafloor
- As it continue to do this, natutulak ung older seafloor eventually at nasisira doon sa subduction zone (which is why hindi lumalaki ang earth)
The process by which the ocean floor sinks beneath a deep-ocean trench and back into the mantle again.
Subduction
Place where seafloor is pushed back into the asthenosphere are called ____________.
Subduction Zone
A central valley formed at the summit of the oceanic ridges as the molten materials continuously flow out from the ridges.
Rift valley
The sea-floor spreading was because of the ___________ (specific process)
Convection Current
Who gave the idea of sea-floor spreading?
Harry H. Hess
What theory was the sea-floor spreading derived from and who founded that theory?
Continental Drift Theory (CDT) by Alfred Wegener
What super continent did CDT refer about? and what was lacking for it to be an accepted theory?
Pangea, which drifted apart from each other.
There was lack of evidence about the breaking/drifting part.
What were Alfred Wegener’s evidences for CDT?
Fossils, Ancient Climate, Jigsaw Puzzle, Landforms
The Earth’s surface is ______ covered with water.
75%
What was the sequence of the theories/ideas connected to this topic:
Continental Drift Theory –> Sea Floor Spreading –> Plate Tectonics
These are any several vast submarine region covering nearly 3/4 of the Earth’s surface.
Ocean Basin
What are the 5 Ocean Basin? which are the 4 that we’ll stick with and why?
Pacific, Atlantic, Southern, Arctic, Indian (PASAI)
Sticking to 4 (Southern not included) because it was understood before na the bottom part were covered diretso by the other oceans.
Ocean Basins.
Largest - Shallowest -
Smallest - Deepest -
Largest - Pacific Shallowest - Arctic (kasi nasa tuktok)
Smallest - Arctic Deepest - Pacific (bcs of mariana trench)
What is bathymetry?
Bathy (bathos): the ocean depth, Metry : to measure = Science of measuring the ocean depth (Charting the sea-floor)
What are the 3 features of ocean basin (methods to map ocean floor)?
Sounding Line, Echo Sounding, Satellite Altimetry
Feat of Ocean Basin. Weighted rope lowered overboard until it touched the ocean bottom; Old method, time consuming, inaccurate.
Sounding Line
Feat of Ocean Basin. SONAR that measures depth by emitting high-freq sound and listening for echo from seafloor. (Property of Reflection)
Echo Sounding
What is SONAR?
Sound, Navigation, and Ranging
Feat of Ocean Basin. The shape of the sea surface
approximates the shape of the seafloor (measures altitude).
Satellite Altimetry
What are the 5 main features of the ocean?
Continental Margin
Abyssal Plains and Abyssal Hills
Mid-Ocean Ridges
Deep-Ocean Trenches
Seamounts and Volcanic Islands