Tectonic Landscapes
1. Distribution of earthquakes and volcanoes
Linear, Along the Coast, At plate boundaries, Clustered together
2. Hotspots
Magma rises from the mantle and plumes towards the surface. At the surface the magma
erupts through the crust. This creates volcanoes that often rise above the ocean surface
to form islands. The Canary Islands formed as the crustal plate moved over the
stationary source hotspot.
3. Formation of Convergent/Destructive Volcano
Convergence of two plates (oceanic and continental) towards each other due to
convection currents leads to subduction of the denser oceanic plate. High
temperatures and friction lead to the melting of the subducted plate. Less dense
material rises through and pressurises the continental crust, creates cracks and a path
for rising magma. Rising magma contains gas and is highly pressurised leading to
explosive eruptions. The cooling and solidifying of magma or ash on the surface forms
a volcano
Feature = Fold mountains = form when the two plates collide. The force of the
collision leads to an up thrust of the plates forming mountains with folded geology
Feature = Volcanoes = formed due to magma rising through the crust (from
subduction). Such volcanoes are often steepwith slopes made of pyroclastic deposits,
and they produce explosive eruptionsdue to high gas content in magma.
Features = Subduction zone, earthquakes, tsunami, ocean trench…
4. Formation of Divergent Volcanoes
1- Convection currents pull plates apart. 2- As the plates move apart, magma from the
mantle rises to fill the gaps and forms new oceanic crust. 3- A mid-ocean ridge is
formed by the new crust. 4- Magma rises due to convection currents, leading to
pressure and doming of the crust (oceanic). Magma rises through the weaknesses in
the crust. Eventually (low viscosity) magma erupts onto the surface. The continued
movement of plates pulls the plates apart leading to more effusive eruptions. Some
may grow to form islands, e.g. Iceland Feature = Ridges = Forms as rising magma
erupts above the sea floor
Feature = Shield volcanoes = Forms as lava forms in a series of layers and builds
up over the surface
Feature = Not explosive / Lava flows gently or effusively
1. Distribution of earthquakes and volcanoes
Linear, Along the Coast, At plate boundaries, Clustered together
2. Hotspots
Magma rises from the mantle and plumes towards the surface. At the surface the magma
erupts through the crust. This creates volcanoes that often rise above the ocean surface
to form islands. The Canary Islands formed as the crustal plate moved over the
stationary source hotspot.
3. Formation of Convergent/Destructive Volcano
Convergence of two plates (oceanic and continental) towards each other due to
convection currents leads to subduction of the denser oceanic plate. High
temperatures and friction lead to the melting of the subducted plate. Less dense
material rises through and pressurises the continental crust, creates cracks and a path
for rising magma. Rising magma contains gas and is highly pressurised leading to
explosive eruptions. The cooling and solidifying of magma or ash on the surface forms
a volcano
Feature = Fold mountains = form when the two plates collide. The force of the
collision leads to an up thrust of the plates forming mountains with folded geology
Feature = Volcanoes = formed due to magma rising through the crust (from
subduction). Such volcanoes are often steepwith slopes made of pyroclastic deposits,
and they produce explosive eruptionsdue to high gas content in magma.
Features = Subduction zone, earthquakes, tsunami, ocean trench…
4. Formation of Divergent Volcanoes
1- Convection currents pull plates apart. 2- As the plates move apart, magma from the
mantle rises to fill the gaps and forms new oceanic crust. 3- A mid-ocean ridge is
formed by the new crust. 4- Magma rises due to convection currents, leading to
pressure and doming of the crust (oceanic). Magma rises through the weaknesses in
the crust. Eventually (low viscosity) magma erupts onto the surface. The continued
movement of plates pulls the plates apart leading to more effusive eruptions. Some
may grow to form islands, e.g. Iceland Feature = Ridges = Forms as rising magma
erupts above the sea floor
Feature = Shield volcanoes = Forms as lava forms in a series of layers and builds
up over the surface
Feature = Not explosive / Lava flows gently or effusively
