EESA06H3 Lecture 5: EESA06 Lecture 5

47 views8 pages
8 Aug 2016
School
Course
Professor
EESA06 Lecture 5 Page 1
EESA06 Lecture 5
When oceans close is the dangerous volcanoes – because of subduction.
Raeology – ability to flow, how easy does that magma flow?
- Iceland is very fluid – not that dangerous, all gases come out
- More viscosious - dangerous, stuff comes out – pyroclastic
- Pyroclastic – broken by fire, rocks are shattered by eruptions and thrown up into air
- Volcanic bombs or ash(is a misnomer - named improperly)
oItaly thought it was coal burning
The Green Areas – subduction back into the mantle
- Friction (earthquakes), melting (volcanoes)
- Similar to lava lamp
The Pacific Ring of Fire: Tectonics of a closing ocean
- Pacific Rim - Dense concentration of volcanes, major
earthquakes, tsunamis
Subduction:
- The stars marks earthquakes - The deepest earthquakes are 700km
down
- We know that slabs don’t melt till after 700km down
- Magmatic Arc – a line of volcanoes directly above subduction
zone
- Oceanic crust – made out of basalt
- Silicic magma - Sediment + seawater melted, reducing viscosiy of magma
- Deep water trenches – ocean floor going down into subduction zone
New Zealand: small island, exposed tip of a much larger land mass (Zealandia)
- Red Boundary - Pacific plate and Austrailian Plate
oBottom: Austrailian Plate is being subducted under Pacific Plate
oTop: Pacific Plate is being subducted under Austrailian Plate (older
oceanic crust is heavier)
oMiddle: Obduction - Colliding continental crust together
- Obduction – Himalayas, creating high mountains
Continential Crust Collides with Continenetial Crust:
- The Southern Alps – Mt.Cook in New Zealand
White Island – young volcano
find more resources at oneclass.com
find more resources at oneclass.com
Unlock document

This preview shows pages 1-3 of the document.
Unlock all 8 pages and 3 million more documents.

Already have an account? Log in
EESA06 Lecture 5 Page 2
- Lateral (side) blast – highly dangerous
- Caused by sector colapse
- Sulfuric acid – natural pollution
Merapi Volcano – Indonesia’s most dangerous
- Killed the gate keeper that protected the volcano
Subduction: Older oceanic crust going under younger crust
- Japan & Indonesia
- When you collide two oceanic crust, creates continential crust, generates new lands
- Proto-continents – first continents
Model of Merapi - Steep Volcano – very susceptible to sector collapse
Eruption:
1) Pyroclastic Flow - White areas – with gas and boulders
2) Lahars – debris flow – similar to concrete
Merapi’s sister – stable
Top of Merapi – very unstable because has thick plug of magma
find more resources at oneclass.com
find more resources at oneclass.com
Unlock document

This preview shows pages 1-3 of the document.
Unlock all 8 pages and 3 million more documents.

Already have an account? Log in
EESA06 Lecture 5 Page 3
being pushed up, building a cap and its beginning to fall off
- Large cracks
When erupts – gase and large masses of rock rolling down
- Pyroclastic flows
- Rich soils – farming at base of volcano
After the pyroclastic flows – the large boulders
- Mt.Winson killed 30 journalists
Flow deposits – burnt stuff buried
- Charred woods – dark oval
Japan: Volcanic arc
- Earthquake nation, most danergous place on pacfic rim
- More volcanoes, active faults
- Tokyo – four plates combined here
Arc of volcanoes becomes an island
Chikyu – the earth
- Drill ship – can drill 7km down into ocean floor
- Made out of derrick – the drilling apparation
- Riser system – can withstand high gas pressures
- Want to drill down into mantle – new source of energy + mineral deposits etc.
- Want to find an early warning system for earthquakes
Mount Fuji and the City of Fujioshida
- Famous for fire festival
- Make offerings to the volcano
- Pyres – light these for celebration
find more resources at oneclass.com
find more resources at oneclass.com
Unlock document

This preview shows pages 1-3 of the document.
Unlock all 8 pages and 3 million more documents.

Already have an account? Log in

Get access

Grade+
$10 USD/m
Billed $120 USD annually
Homework Help
Class Notes
Textbook Notes
40 Verified Answers
Study Guides
1 Booster Class
Class+
$8 USD/m
Billed $96 USD annually
Homework Help
Class Notes
Textbook Notes
30 Verified Answers
Study Guides
1 Booster Class