lecture 1

Question 1

1. From what word is the “volcano” derived from?
2. And this derived form of a volcanic Italian island (north of Sicily) after who (who is he)?

Answer 1

1. Vulcano, the name of a volcanic Italian island in the north of Sicily.
2. The island is named after Vulcan, the ancient Roman god of fire.

Question 2

1. Where is situated Mount Saint Helens?
2. What is it known for concerning its continuously eruption streak (from when to when)?
3. How did YAKAMA Nation refers to mount Saint Helens?
4. What is the legend surrounding it?

Answer 2

1. Volcano situated in Washington State.
2. For being the most disastrous eruption in 1980 in US history (erupted from 2004-2008)
3. As “Si Yett”=woman
4. Mount Saint Helens was a beautiful
   maiden placed on Earth to protect the bridge of the gods on the Columbia River from two battling brothers + The battling brothers were Mount Adams and Mount Hood, two other volcanoes in the area, considered potentially active and dormant, respectively!

Question 3

1. What is a volcano in simplest terms?
2. What are the Earth’s layers?
3. What is the difference between the inner and the outer core?

Answer 3

1. It is an opening on the surface of the Earth
2. Core (inner core and outer core), mantle, crust
3. OUTER CORE consists of MOLTEN ROCK but INNER CORE contains SOLID ROCK due to high pressures.

Question 4

1. What are the different layers made up of?
2. What can escape onto Earth’s CRUST through volcanoes?

Answer 4

1. MANTLE and CRUST are mostly SOLID ROCK, varying temperatures and pressures can result in presence of MOLTEN ROCK in lower portions of CRUST and MANTLE.
2. Molten rock or magma

Question 5

1. From where do volcanoes allow molten or semi-molten rock known as MAGMA to rise up from?
2. What does magma consist of?

Answer 5

1. The lower portions of earth’s CRUST and the upper portions of the MANTLE and erupt/escape onto earth’s surface.
2. liquified rocks (known as melt), crystallized minerals, solid rocks (that are pulled into the melt) and dissolved gases (including water vapour)

Question 6

What is the difference between magma and lava?

Answer 6

Magma is BENEATH Earth’s surface- it may contain suspended mineral crystals and gases along with rock (T°: 600°C-1300°C) and lava is ON Earth’s surface- it may contain suspended mineral along with rock (T°: 700°C-1200°C)

Question 7

1. What is the km of each layer?
2. What is Earth’s thickness (diameter)?

Answer 7

1. Inner core=1220km
   Outer core=2250km
   Mantle=2900km
   Crust= ocean crust 5-7km and continental crust 10-75km
2. 12740km

Question 8

1. Which part of the crust is denser?
2. What does the lithosphere include?

Answer 8

1. The OCEAN CRUST (aka OCEANIC CRUST) is
   thinner but denser than the CONTINENTAL
   CRUST.
2. The outermost layers of Earth;
   namely the upper portion of the MANTLE + the
   CRUST.

Question 9

Name the 4 spheres of earth and what does it include.

Answer 9

1. Lithosphere: The outermost layers of Earth;
   namely the upper portion of the MANTLE + the
   CRUST
2. Hydrosphere: All WATER on or near Earth’s surface
3. Atmosphere: The GASES surrounding our
   planet and held in place by Earth’s GRAVITY. Most gases are close to Earth’s surface in the lowest region of the ATMOSPHERE called the TROPOSPHERE
4. Biosphere: All LIVING ORGANISMS on Earth

Question 10

1. What is plate tectonics?
2. In what can the lithosphere be divided?
3. Name the 7 major tectonic plates and the 8 minor ones.

Answer 10

1. A theory by which TECTONIC PLATES and their movements are employed to explain
   landforms (e.g., mountain building - formation of trenches/ridges), earthquakes and VOLCANOES
2. Into large rocky plates known as TECTONIC PLATES
3. a) North America Plate, South America Plate, Eurasian Plate, Australian Plate, African Plate, Antarctic Plate and Pacific Plate
   b) Juan de Fuca Plate, Cocos Plate, Nazca Plate, Caribbean Plate, Scotia Plate, Arabian Plate, Indian Plate and Philippine Sea Plate

Question 11

1. What is asthenosphere?
2. What does it move due to?
3. What happens to tectonic plates?

Answer 11

1. partially molten layer of MANTLE
2. moves due to heat transfer and rise and fall of partially molten rocks within it
3. When ASTHENOSPHERE below moves, TECTONIC PLATES are dragged along and move too

Question 12

What movement can tectonic plates have?

Answer 12

pull away from one another (divergent plate boundary), collide into one another (convergent plate boundary) and slide along one another (transform plate boundary)

Question 13

1. Compare densities according to ocean and continental crust.
2. What happens upon collision?

Answer 13

1. -if TECTONIC PLATE is under OCEAN CRUST then it will be DENSER and THINNER.
   -if TECTONIC PLATE is under land (i.e., CONTINENTAL CRUST), then it will be LESS DENSE and THICKER
2. DENSER TECTONIC PLATE (like ocean crust) will slide under a LESS DENSE PLATE (like continental crust)

Question 14

1. Where are divergent plates especially encountered?
2. What do we find there?
3. What is a ridge?

Answer 14

1. Under ocean floors
2. Volcanic activity and earthquakes are often encountered along DIVERGENT PLATES, particularly along the mid-ocean RIDGES
3. A long, narrow, raised part of Earth’s
   surface (e.g., long, narrow mountain chains).
   The sides of the RIDGE slope away from the
   narrow top known as a CREST

Question 15

1. What is the percent of volcanic activity that occurs under water, along mid-oceanic ridges?
2. If they were all linked together how long would it be?

Answer 15

1. 70%
2. 60 000 km

Question 16

1. What happens whenever plate carrying OCEAN CRUST collides with a plate carrying CONTINENTAL CRUST?
2. What is a subduction zone?

Answer 16

1. the OCEAN CRUST (and plate)
   sinks below the CONTINENTAL CRUST
   (and plate) due to its greater density.
2. OCEAN CRUST sinking beneath CONTINENTAL CRUST

Question 17

1. What happens when a plate sinks?
2. What is sand?

Answer 17

1. The sinking of one plate drags tonnes of sediment into the molten MAGMA below. This alters the MAGMA and results in a thick MAGMA
   rich in SILICA (silicon dioxide).
2. Sand = silicon dioxide (SiO2), aka quartz

Question 18

1. What is something special that happens along subduction zones?
2. What does it create?

Answer 18

1. Thick, gummy magma of volcanoes along
   SUBDUCTION ZONES does not flow as easily once it erupts as LAVA (releasing lots of gases in the process –mainly H2O, CO2, SO2).
2. Since the LAVA does not flow away so easily, we get a tall, cone-shaped volcano known as a
   STRATOVOLCANO

Question 19

Name 4 famous stratovolcanoes.

Answer 19

Mount Saint Helens (USA), Mount Vesuvius (Italy) and Mayon (Philippines), Mount Fuji (Japan-it is still active)

Question 20

1. What result are seen along transform plate boundaries?
2. Give an example of it.

Answer 20

1. It can often result in earthquakes due to built up stress caused when plates get stuck and subsequently manage to slide by one another.
2. San Andreas Fault along the Western USA