Sorry to correct you: There is no downgrade of the Richter scale - it's an urban legend introduced by the Nibiru- and Earthquake-Tards.

The Richter scale was replaced by the Moment magnitude scale in the early 1980th because it's more accurate, especially when the neares seismometer is far away from the epicenter.
Since more than 30 years the Richter scale is not in use any more.
Even if the media refer to the Richter scale in reality it's the MMS.

I this case there were three stations close by. Thus the 7.7 Mw (MMS) may by something between 7.6-7.8 ML (Richter) but far away from an 8.5.

In general:
Small quakes 3-: Mw < ML
Moderate quakes 3-6: Mw = ML
Big quakes 7+: Mw > ML


MMS: [link to en.wikipedia.org]


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