Module 1 - formation of the earth Flashcards
How was the solar system formed?
-The sun and the rest of our solar system were formed from a giant, rotating cloud of gas and dust known as the solar nebula.
-the solar system was formed approximately 4.6 billion years ago from the dust and gas debris from a supernova.
-The Sun formed in the centre, and the planets formed in a thin disk orbiting around it.
How was the Geosphere formed?
How was the Atmosphere formed?
-Formed from gases spewed from volcanoes.
How was the Hydrosphere formed?
-Formed from water contained in the minerals after the earth had cooled from the volcanoes.
What are seismic waves?
-They are waves that travel through the earth produced by an earthquake.
What are the two types of seismic waves?
-Body waves, are produced first and travel through the layers of the earth.
-Surface waves, travel slowly at the planets surface.
What are the two types of seismic body waves and how do they provide evidence of earths layers?
-P waves (Primary) , are longitudinal waves and can travel through both solids and liquids. They are refracted as they pass through different densities.
S waves (Secondary) , are transverse waves that can only travel through solids. They have a larger shadow zone as they cannot go through liquids.
What is the lithosphere and its factors?
-The rigid outer part of the earth, consisting of the crust and upper mantle.
What is the Asthenosphere and its factors?
-The upper layer of the earth’s mantle, below the lithosphere.
-weak and plastic liquid-like
What are the compositional layers of the earth?
- Crust-the outermost layer of the earth, continental crust is thicker and older, and the oceanic crust is denser and younger.
- Mantle- the upper mantle is the solid part of the mantle (AKA lithosphere), the asthenosphere is the plastic liquid-like and weaker part of the mantle, and the Mesosphere is the semi-fluid boundary between the mantle and core.
- Core- the outer core is the liquid layer of the core, it is the thickest. the inner core is the solid layer of the core, it is the hottest and both layers consist of iron and nickel.
What are isotopes?
-They are elements with the same number of protons but different numbers of neutrons.
-They have the same chemical properties but different mass.
What is radiometric dating?
Determining the exact age of isotopes
What is relative dating?
Determining if one rock is older or younger without a specific age of the rock.
What is a half life?
-The time is taken for half of the radioactive parent atom to decay into the daughter atom.
How do meteorite show evidence for the age of the earth?
-The composition of all meteorites in the solar system tells us what the Earth is made of, so we can guess that elements that are common in meteorites but not on Earth’s surface are more common inward.
-With radioactive dating scientists can determine the age of the meteorites and also the age of the earth.
