Flashcards in earth science mid term Deck (46):
What is the building block of most substances?
What is the difference between atoms and ions?
Atoms have the same number of protons and electrons and Ions have different numbers of protons and electrons.
What is a mineral? (List the five properties of a mineral.)
A solid Inorganic substance of natural occurrence. Streak, Color, Hardness, Luster, Crystal Shape
What physical properties are used to identify minerals? Minerals are identified by physical and chemical properties
color,streak, luster,crystal shape,hardness,cleavage, fracture, specific gravity and reaction to an acid.
What are rocks?
A naturally formed group of minerals bound together.
How are rocks classified?
Describe the processes that form the three types of rock.
Igneous-solidified magma or lava upon cooling. Sedimentary-accumulation of particles. Metamorphic-Either exposed to pressures or exposed to very high temperatures, altering its structures.
What are the layers of the earth? What is the Moho?
The Crust, The Mantle, The Outer Core, The Inner Core. The Moho is the boundary between the crust and the mantle.
What do we know about the layers of the earth?
What happens as one goes deeper into the Earth’s interior?It gets hotter the deeper you go down.
What elements are abundant in the crust?
Oxygen, Silicon, Aluminum, Iron, Calcium, Sodium, Magnesium,Potassium,Titanium, Hydrogen.
What is Pangaea?
A super continent that broke apart to make other continents.
What is sea floor spreading?
a process that occurs at mid-ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge. Seafloor spreading helps explain continental drift in the theory of plate tectonics. When oceanic plates diverge, tensional stress causes fractures to occur in the lithosphere.Magma rises up the fractures and cools on the ocean floor to form new sea floor
Where is the seafloor old and young?
Older rocks will be found further away from the spreading zone while younger rocks will be found nearer to the spreading zone.
What does the seafloor look like? (List at least five features of the seafloor.)
Continental Shelf, Continental Slope, Trenches, Abyssal Plains, and Mid-Ocean Ridges.
What world event led to technology being created that was used to map the seafloor?
The first Sonar type listening device in 1906, as a way of detecting icebergs. Interest in Sonar was increased during World War II when there was a need to be able to detect submarines.
What do scientists use to map the seafloor?
They use sonar or echo sounding, sediment sampling and satellite observation.
How are submarine canyons formed?
Turbidity currents, which are underwater avalanches of sediment, carve out the submarine canyons in the continental shelf.
What is the difference between a seamount and a guyot?
A Seamount is formed by a projection rising above sea level (lava); also formed by volcanoes and coral build up. a Guyot is a seamount that's top has been "cut off" (eroded away).
Where are the majority of the trenches located?
Around the rim of the Pacific Ocean .It is the converging boundaries of two tectonic plates, with one submerged under the other, this explains the trenches and the frequent seismic activity in the area (also know as the Ring of Fire).
What is plate tectonics?
The Earth’s Lithosphere or crust is divided into large pieces, or plates, that sit on the molten interior of the planet. Understanding how plates move and interact is the main purpose of plate tectonics.
How much do the plates move each year?
About as much as your finger nails grow.
What makes the plates move?
Currents within the interior cause the plates to move, which causes many different geological events, including earthquakes and the forming of mountains and volcanoes.
How do the plates meet?
By forming mountains or deep trenches.
What are the three types of faults? (Be able to identify what they look like.)
Normal faults form when the hanging wall drops down. Reverse faults form when the hanging wall moves up.
Together, normal and reverse faults are called dip-slip faults, because the movement on them occurs along the dip direction—either down or up. Strike-slip faults have walls that move sideways, not up or down.
What is the difference between an anticline and a syncline?
An anticline is a fold in rocks that goes up and a Syncline is a fold that goes down.
What processes occur at plate boundaries?
The plates are pushing towards each other or pulling way or sliding past. Also they are areas of high heat where molten rock moves up to Earths surface.
What causes most earthquakes?
When the strain along plate boundaries becomes so strong it forms fractures. Also volcanos, cavern collapse, meteor hit.
Where do most earthquakes occur?
Along plate boundaries. In the Pacific Ocean.
What are the parts of an earthquake?
What are the types of earthquake waves?
What is the relationship between them? Body Waves are made up of P Waves formed by compression and expansion and S Waves cause particles of rocks to move at right angles in the direction the wave is traveling. Both S and P waves cause Surface Waves.
What does the Richter scale tell scientists?
The magnitude of an earthquake.
What is a seismograph?
It detects and record waves produced by Earthquakes.
How does silica and dissolved gases affect the explosiveness of a volcano?
Silica affects the magmas viscosity or ability to flow. More Silica means less flow. Gases that are trapped in the magma flow can expand and cause a more violent eruption.
What are the parts of a volcano
Magma - Molten rock beneath Earth's surface.
Parasitic Cone - A small cone-shaped volcano formed by an accumulation of volcanic debris.
Sill - A flat piece of rock formed when magma hardens in a crack in a volcano.
Vent - An opening in Earth's surface through which volcanic materials escape.
Flank - The side of a volcano.
Lava - Molten rock that erupts from a volcano that solidifies as it cools.
Crater - Mouth of a volcano - surrounds a volcanic vent.
Conduit - An underground passage magma travels through.
Summit - Highest point; apex
Throat - Entrance of a volcano. The part of the conduit that ejects lava and volcanic ash.
Ash - Fragments of lava or rock smaller than 2 mm in size that are blasted into the air by volcanic explosions.
Ash Cloud - A cloud of ash formed by volcanic explosions.
How do volcanoes affect humans?
We need to be able to predict when they erupt to avoid tragedy.
What type of sediment would be carried the farthest by a river into a lake?
The smallest silts and clays.
What causes most weathering?
Mechanical or Chemical processes.
List examples of mechanical weathering?
wetting and drying,
abrasion by rock plant and animal activity
Where is most of the fresh water found on Earth?
Frozen in glaciers and icebergs.
List some things that can affect the amount of runoff in an area?
The steepness of the ground, amount of vegetation and impermeable barriers.
When do droughts occur?
When there is a lack of rain over a long period of time. If rain does occur it usually isn't enough for the ground to absorb before it is evaporated again.
What is groundwater?
Water that enters and is stored in the ground
What is the: the zone of saturation
is when rain falls and soaks down to an impermeable material and begins to back up into all the pores above the material.
The upper surface of the zone of saturation zone of aeration,-between the water table and the surface there is a section of the ground that can still hold some water.
What watershed is Coatesville in?