Unleash the Marvels of Science with Our Class Notes!
Embark on a journey through the earth with our expertly-crafted science notes. Each page ignites curiosity and sparks discovery. Dive in and explore the wonders of the natural world like never before!
This document includes our science class ...
Science Q1 Reviewer
LAYERS OF THE EARTH
Geology - studies the structure of the earth origin and development
Major Layers of the Earth:
i. Crust
ii. Mantle
iii. Core
Crust
- outermost layer of the earth
- very thin layer of solid rock; thinnest layer
- 5-35 km thick beneath the land and 1-8 km thick beneath the ocean
- broken into many pieces called plates, the movement of these plates causes earthquakes.
Mantle
- the layer beneath the crust
- 2900 km thick hence, it is the thickest/largest layer
- it includes the lithosphere and asthenosphere
- flexible; flows like very viscous liquid
- very hot - 1600°F at the top and 4000°F towards the center of the Earth.
- mostly made up of silicate and molten rocks
Core
- the core of the Earth is like a ball of very hot metals
- it is subdivided into two layers; inner core & outer core
- so hot and has so much pressure that if you were to go there—you would be squished into something even
smaller than a marble.
Outer core
- made up of molten iron and nickel
- 4000-9000°F.
- 2,250km thick.
Inner core
- made up of solid iron and nickel
- The inner core is solid metal due to the extreme heat and pressure.
- 9000°F
- 800km thick
Lithosphere
- the lithosphere is part of the crust and the upper part of the mantle (the top 100 km).
- It is composed of hard, brittle rock
- The lithosphere is subdivided into portions called lithospheric plates
Asthenosphere
- the asthenosphere is the part of the mantle underneath the lithosphere.
- it is made of molten rock and metal so that it “flows” like hot asphalt.
- the asthenosphere is the part of the mantle that moves and causes the tectonic plates of the crust to move as
well.
Theories:
Plate Tectonic Theory - states that the crust is composed of different plates which move either towards,
away or past each other. The modern version of the Continental Drift Theory of Alfred Wegener
Plates- the moving, irregularly-shaped slabs of solid rocks that fit together to form the surface of the Earth.
Tectonics-branch of geology that deals with the movements that shape the Earth’s crust
, Science Q1 Reviewer
Continental Drift Theory - this theory states that the Earth was once composed of only one
supercontinent called Pangaea. Through time, this supercontinent split into two sub-continents, Laurasia
and Gondwanaland.
- Million years further, Laurasia split into a few smaller continents forming the continents in the northern
hemisphere of the Earth. This includes Asia, Europe, North America, South America, and Africa. On the other
hand, the continents of the southern hemisphere, Australia and Antarctica, are the two continents divided from
Gondwanaland
PLATE BOUNDARIES
Plate Tectonics
Tectonics - branch of Geology that deals with the movements that shapes the earth's crust.
Plates - large rigid slab of solid rock.
o The plates "flows" on the slowly flowing asthenosphere
o The plates include both land and ocean floor
The Mohoriovicic discontinuity or Moho is the boundary between the crust and the mantle.
What drives Plate Tectonics?
- the slow movement of hot softened mantle lies below rigid plates.
- the hot, softened rock in the mantle moves in a circular manner in a convection flow
What are Plate Boundaries?
- the border between two tectonic plates
- It is a three-dimensional surface or zone across which there is significant change in the
velocity(speed/direction) of one lithospheric plate relative to adjacent lithospheric plate
Boundaries - a line that limit of an area in short, a dividing line
Different types of Plate Boundaries
Convergent Plate Boundaries
- It occurs where two plates are pushing towards each other.
- Two plates are moving towards each other in which one plate slide underneath the other (this process is
called subduction)
- This type of Plate Boundary is also known as DESTRUCTIVE PLATE BOUNDARY
Subduction a process in which 1 plate goes underneath the other due to its greater density.
Subduction zone - the area in which the subducting plate subducted
Subducting plate - is the plate that goes underneath the other plate called overriding plate
Trench - is a narrow excavation made below the surface of the ground because of the movement of plates.
1. Oceanic-Oceanic Convergence
- During this convergence, Older oceanic crust or plate will subduct or push underneath the younger oceanic
crust because older oceanic crust is denser than younger oceanic crust or plate.
Geologic Process: Subduction Process, Formation of Magma
Geologic Features: Trench, Volcanic Island Arc
Geologic Events: Tsunami, Earthquakes
2. Continental-Oceanic Convergence
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller cindyrellamn. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £5.88. You're not tied to anything after your purchase.
