Chapter 2 Flashcards
What are the sections of the earth?
Inner core
-Solid, mostly iron and nickel
Outer core
-Liquid, mostly iron
Mantle
-Semi solid layer of rock that helps transports portions of the overlying crust
Crust
-Solid outer layer of Earth
Is continental crust lighter than oceanic crust?
Yes
Continental crust typically contains a greater amount of lighter elements than oceanic crust of similar volume
Does subtle difference in density influence how continental and oceanic crust of different plates interact?
Yes
What are the probable composition of Ocean and Continental crusts?
Oceanic crust probable composition is basalt
Continental Crust probable composition is granite
What are Plate tectonics?
the large scale motion plates of the Earth’s lithosphere
What is seafloor spreading?
occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge
What is subduction?
takes place at convergent boundaries plates where on plate moves under another and is forced or sinks because of gravity into the mantle
Ocean crust sinks
Continental crust floats
Are tectonic regions complex?
Yes
What are the three types of plate boundaries?
Diverging Boundaries
Converging boundaries
Transform boundaries
What is Diverging Boundaries?
Where the plates move apart
From rift zones
What are converging boundaries?
Where plates collide
From subduction zones, where trenches are produced, or thrusts zones, where mountains are formed
Pressure and friction from subduction melt rock which emerges as volcanoes in cracks along the edge of the oceanic crust
What is transform boundaires?
Where one plate slides past each other in opposite directions
Where is oceanic islands commonly formed?
Along subduction zones
Where are hot spot volcanoes formed?
where plumes of superheated mantle melt through overlying plate
How are series of islands formed?
A series of islands may form as the plate migrates over the hot spot
How are mountains and islands made?
Plate movements can result in vulcanisms, leading to mountain formation on continental crust and island formation on oceanic crust
Hot spot volcanism is another way island can form
As oceanic crust subducts, series of islands or mountains are formed
What is the estimated time the Earth was formed?
~4.5 BY(Billion Years) ago
What is the estimated time Guam was made?
44 MY(Million Years) ago
Is Guam’s Geological History Complex?
Yes
What is Limestone made out of?
Calcium carbonate, it dissolves in water
Explain the Geo Map of Guam
Volcanic formations primarily in S Guam
Limestone formations primarily in N Guam
Formations become exposed through tectonic uplift
Geology influences the regional soils, hydrology, and biology of Guam
Did northern Guam use to have an atoll?
Yes
What reduced carbonate sediment?
Erosion and dissolution
How is an Atoll island formed?
from coral rubble piled up from wave activity
What is climate?
the long term pattern of factors such as temperature, rainfall, day length, and their seasonal changes
the long term atmospheric conditions for a particular area
What is weather?
the shorter term variations in atmospheric factors (wind, humidity, rainfall, etc.)