Transcript Tectonic Landforms

Tectonic
Landforms
Hotspots / Fold Mountains / Ocean
Trenches / Island Arcs / Ocean Ridges
Tectonic Landforms
• Each type of plate boundary displays its
own distinctive combination of
processes and resultant landforms.
• The global pattern of tectonic landforms
= closely linked to global pattern of plate
margins.
Fold Mountains
• Found either along continental
landmasses (The Andes) or where
continental land masses abut each
other (Himalayas).
• Form a linear pattern (hence ‘Fold’ or
‘Chain’ mountains.
How Formed?
• Formed by compression resulting from the
convergence of two plates.
• Either at collision (Himalayas) or destructive
(Andes) margins.
• Anomaly = The Urals
Outcome of crustal crumpling due to
compressional forces exerted at the plate
edges.
Task 01
• Label: Alps, Southern Alps, Urals,
Pyrenees, Atlas Mountains, Andes,
Rockies.
Location of Fold Mountains
Ocean trenches
• Also have a Linear pattern.
• Most located just offshore (Peru-Chile
trench).
How Formed?
• Formed at subduction zones where the
oceanic plate subducts beneath continental
plate.
• Some ocean trenches occur further offshore
e.g. The Mariana Trench in the Pacific Ocean
= the convergence of two areas of oceanic
crust and the subduction of the heavire of the
two plates.
Task 02
• Label:
Peru-Chile Trench / Tonga Trench /
Mariana Trench / Japan Trench /
Philippines Trench / Kuril Trench /
Aleutian Trench / Java Trench
Location of Ocean Trenches
Island Arcs
• Found in a linear pattern although the
tend to be curved or arc-shaped.
• Usually located offshore e.g. the
Mariana Islands.
How formed?
• Formed at destructive plate margins where
two areas of oceanic crust converge.
• The subducted crust melts and the lowdensity molten material rises, aided by the
compressional forces from the convergence,
to form a chain of volcanic islands.
• Where the edge of the subducting plate is
curved in shape (the Pacific Plate) = The
islands form an arc.
Task 03
• Label:
Sunda Islands / Kuril Islands / Aleutian
Islands / Mariana Islands / Leeward
Islands / Japan / Philippines
Location of Island Arcs
Ocean Ridges
• Also occur in linear pattern.
• Normally extending through the middle
of oceans (mid-Atlantic ridge).
• Occur at constructive plate margins –
where two oceanic plates are diverging.
• Their mid-oceanic position is due to the
creation of oceans in which they lie.
How formed?
• The continents to which they were joined first
separated at the break up of Pangea.
• Anomaly = The East Pacific Ridge
This is down to the position of convection cell
currents in the asthenosphere producing
rising and diverging limbs at that particular
place.
Task 04
• Label:
East Pacific Ridge / Pacific Antarctic
Ridge / Mid-Indian Ridge / Carlsberg
Ridge / Atlantic-Indian Ridge / MidAtlantic Ridge
Location of Ocean Ridges