🦋 🦋
UNIT 11 - EARTHQUAKES & VOLCANOES
BUTTERFLY . SPINEL
,11.1 🦋—--------------------------------------------
🫧Earthquakes and volcanoes occur everyday in the world.
🫧500,000 earthquakes every year
🫧100,000 strong earthquakes every year
🫧100 major earthquakes every year
…
🫧Natural disaster → when a natural event causes great damage or loss of life
🫧Natural hazard → when a natural event threatens to cause great damage and
loss of life
…
🫧THE “-SPHERES”
● Atmosphere
● Lithosphere
● Biosphere
● Hydrosphere
#Earthquakes and volcanoes occur in the lithosphere! ^_^
…
🫧LITHOSPHERE
- Rigid outer layer of Earth, made up of upper mantle & crust
…
🫧TONGA VOLCANIC ERUPTION
● January 15, 2022
● Recorded as the largest explosive eruption of 21st century in Tonga
…
,11.2 🦋—--------------------------------------------
🌿PANGEA
● Alfred Wegener (German meteorologist)
● Wegener’s theory 1912; continental drift
● Argued that millions of years ago, the continents were joined together into
one supercontinent - Pangea
● Evidence → similar animal fossils and rock types found on different
continents
● Britannica “Pangea”
● Major weakness → could not explain what great force could be strong
enough to move massive continents
…
🌿CONTINENTAL DRIFT
● Movement of continents and tectonic plates, which is driven by convection
in the mantle
…
🌿Why did Wegener think that that fossil evidence showed that the
continents have once join?
● They looked like they fit together
● Scientists didn’t agree back then because he was unable to explain what
great force could be strong enough to move massive continents
…
, 11.3 🦋—--------------------------------------------
🍥Exploring the ocean floor
● The US Navy during WW2 mapped the ocean floor to find enemy
submarines to find out that the ocean floor is flat.
…
🍥Mid ocean ridge → continuous mountain range found on ocean floor
…
🍥Ocean trench → long, narrow, deep, depressions on the ocean bed
…
🍥US SCIENTIST HARRY HESS
● Proposed new theory of “seafloor spreading”
● Proposed that Wegener was right that the continents have spreaded out
due to growing seafloor.
● New (younger) ocean floors forming at the ridges & slowly moving away
and turning into older ridges.
…
🍥Mountain belts → long chains of mountains
…
🍥Deepest trench on Earth → Pacific Ocean, near the Phillipines’ Mariana
Trench which is 2,500 km long, 70 km wide, 11km deep
…
UNIT 11 - EARTHQUAKES & VOLCANOES
BUTTERFLY . SPINEL
,11.1 🦋—--------------------------------------------
🫧Earthquakes and volcanoes occur everyday in the world.
🫧500,000 earthquakes every year
🫧100,000 strong earthquakes every year
🫧100 major earthquakes every year
…
🫧Natural disaster → when a natural event causes great damage or loss of life
🫧Natural hazard → when a natural event threatens to cause great damage and
loss of life
…
🫧THE “-SPHERES”
● Atmosphere
● Lithosphere
● Biosphere
● Hydrosphere
#Earthquakes and volcanoes occur in the lithosphere! ^_^
…
🫧LITHOSPHERE
- Rigid outer layer of Earth, made up of upper mantle & crust
…
🫧TONGA VOLCANIC ERUPTION
● January 15, 2022
● Recorded as the largest explosive eruption of 21st century in Tonga
…
,11.2 🦋—--------------------------------------------
🌿PANGEA
● Alfred Wegener (German meteorologist)
● Wegener’s theory 1912; continental drift
● Argued that millions of years ago, the continents were joined together into
one supercontinent - Pangea
● Evidence → similar animal fossils and rock types found on different
continents
● Britannica “Pangea”
● Major weakness → could not explain what great force could be strong
enough to move massive continents
…
🌿CONTINENTAL DRIFT
● Movement of continents and tectonic plates, which is driven by convection
in the mantle
…
🌿Why did Wegener think that that fossil evidence showed that the
continents have once join?
● They looked like they fit together
● Scientists didn’t agree back then because he was unable to explain what
great force could be strong enough to move massive continents
…
, 11.3 🦋—--------------------------------------------
🍥Exploring the ocean floor
● The US Navy during WW2 mapped the ocean floor to find enemy
submarines to find out that the ocean floor is flat.
…
🍥Mid ocean ridge → continuous mountain range found on ocean floor
…
🍥Ocean trench → long, narrow, deep, depressions on the ocean bed
…
🍥US SCIENTIST HARRY HESS
● Proposed new theory of “seafloor spreading”
● Proposed that Wegener was right that the continents have spreaded out
due to growing seafloor.
● New (younger) ocean floors forming at the ridges & slowly moving away
and turning into older ridges.
…
🍥Mountain belts → long chains of mountains
…
🍥Deepest trench on Earth → Pacific Ocean, near the Phillipines’ Mariana
Trench which is 2,500 km long, 70 km wide, 11km deep
…
