I believe it was 7.0.
There are a number of earthquake magnitude scales, including the moment magnitude scale (the scale currently favoured by seismologists), the Richter or local magnitude scale and the surface wave magnitude scale.
The most commonly referred to scale by the press and the public is the Richter scale for measuring earthquake magnitude. However this was actually replaced in the 1970s by the Moment Magnitude scale which is the magnitude scale favoured and in use by seismologists.
Richter Scale~
The Richter Scale
The 2011 earthquake was a 5.8 magnitude on the Richter scale.
The magnitude of the 2010 Haiti earthquake on the Richter scale was 7.0
An earthquake's magnitude is expressed as a number on the Richter Scale.
An earthquake is measured by a seismometer to determine its magnitude on the Richter Scale. The Richter is based on a base 10 logarithm. The scale defines magnitude by a logirithm of the ratio of the amplitude of seismic waves.
Magnitude
There are a number of earthquake magnitude scales, including the moment magnitude scale (the scale currently favoured by seismologists), the Richter or local magnitude scale and the surface wave magnitude scale.
The scale currently used to express the magnitude of earthquakes is the Richter scale or the moment magnitude scale (Mw). The moment magnitude scale is more commonly used today as it provides a more accurate measurement of an earthquake's size compared to the Richter scale.
Richter scale
The most commonly referred to scale by the press and the public is the Richter scale for measuring earthquake magnitude. However this was actually replaced in the 1970s by the Moment Magnitude scale which is the magnitude scale favoured and in use by seismologists.
The Richter scale
Richter Scale~
The Richter Scale
The Richter scale measures the magnitude of seismic waves produced by an earthquake, which provides an estimate of the energy released at the earthquake's source. A higher Richter scale number indicates a stronger earthquake.