At magnitude 8.2 and 647 km depth, this was the largest deep-focus earthquake ever recorded at the time and remains the largest in South America.
Key Facts
- Magnitude
- 8.2 Mw
- Focal depth (Harvard CMT)
- 647 km km
- Focal depth (USGS)
- 631.3 km km
- Distance from Reyes
- 55 km NNW km
- Date and time
- June 8, 1994, 20:33 local time
By the Numbers
Location
Cause → Event → Consequence
Deep-focus earthquakes of this type occur at subduction zones where a tectonic plate descends into the mantle at extreme depths. The Nazca Plate subducting beneath South America produces seismic activity hundreds of kilometres below the surface, where unusual stress conditions allow ruptures of exceptional magnitude.
On June 8, 1994, an earthquake of magnitude 8.2 Mw struck beneath the Amazon jungle of Bolivia, approximately 55 km NNW of Reyes, at a focal depth exceeding 630 km. Its epicenter lay in a sparsely populated region, and it was recorded as the largest earthquake globally since the 1977 Sumba earthquake.
The earthquake was later surpassed in magnitude within four months by an 8.3 Mw event in the Kuril Islands. It remains tied with the 2018 Fiji earthquake as the second-largest deep-focus earthquake ever recorded, behind the 2013 Sea of Okhotsk earthquake, and retains the record as the largest deep-focus earthquake in South America.