On average only one earthquake each year is magnitude 8 or higher. Worldwide there are on average 15 earthquakes per year with a magnitude 7.0 or higher.
As of August 2016, the last major earthquake was magnitude 8.3 near Illapel, Chile (2015-09-16 22:54:32 UTC) . The last 9.1 magnitude quake hit off the coast of Japan on March 11, 2011.
For a complete list see related links below to visit the USGS Earthquake Hazards Program web site.
Small foreshocks that precede a major earthquake can occur
i think it was when the earthquake happened last year
yes
The earthquake of Japan occured because Japan is on a major fault line.
Volcanic eruptions
The friction between the plates. When the friction is resolved, an earthquake occurs.
alot of earthquakes
Along the San Andreas Fault in California is one likely place for an earthquake.
It could be days or YEARS before the major earthquake. Plate tectonics are always moving.
Yes. There is normally some level of earthquake associated with a volcanic eruption. It can be mild or a major quake.
Haiti
Haiti.