understand the distribution of earthquakes and volcanoes.
To begin, knowledge of plate tectonics gives us the explanation for formation of volcanoes and
occurrence earthquakes. Volcanoes are result of rising magma from beneath the surface of the
earth that is released on the surface of the earth's crust. As such, plate convergence and
divergence, as well as hotspot activities can result in volcanoes. On the other hand,
earthquakes are results of relief of stress that has been accumulated between the margins of
two plates, or when there's violent volcanic activities that sends out seismic waves in the
ground. Shallow focus quakes thus occurs along transform faults where plates are moving in
different direction relative to each other; deep focus quakes occurs along convergent plate
boundaries where subduction occurs.
The majority of all volcanoes on earth are distributed along major convergent and divergent
plate boundaries. The Pacific Ring of Fire, which connects the convergent margins between
Pacific Plate and a couple of the other plates, happens to be where most of earth's volcanoes
are distributed. This is explained by the activity subduction activities occurring along these
plate margins. These subduction volcanoes are mainly stratovolcanoes and produce acidic lava.
The shield volcanoes that produce basaltic lava, on the other hand, are distributed along the
main divergent plate boundary like along the Mid-Atlantic Ridge, which connects the North
America-Eurasia divergent boundary with the South America-African divergent boundary.
Hotspot volcanoes are distributed within plates, like at the Hawaiian Islands, in the middle of
the Pacific plate.
Earthquake activities are distributed in similar locations as the stratovolcanoes in the Pacific
Ring of Fire, especially the deep focus quakes as these areas are where subduction produces
the stress between the plates that are occasionally released. On the other hand, at divergent
boundaries, the tensional forces between plates rarely cause any stress build up. However, the
transform faults that are results of differential rates of divergence would accumulate strain
that is released through shallow focus quakes. At other conservative plate boundaries, shallow
focus quakes are also common, such as along the San Andreas Fault between the Pacific Plate
and the North American plate.
In conclusion, the knowledge of plate tectonics helps explain the formation of volcanoes and
occurrence of earthquakes thus allowing us to understand the distribution of these tectonic
features based on the knowledge of plate location and the type of boundaries between the
plates.
