Shake, rattle and roll - not so many earthquakes in Loja


Fault Lines, Map 1
Earthquakes, tsunamis, volcanoes, oh my!

You probably know that Ecuador sits on the infamous Ring of Fire - the zone of seismic activity that surrounds much of the Pacific Ocean. More specifically, the Nazca Plate is subducting the South American Plate just off the coast of Ecuador. That process accounts for the Andes mountains being pushed up as the Nazca Plate dives underneath them.

There are several fault lines created by the subduction that run through the country. The largest (called the Dolores-Guayaquil Megashear) goes from near Guayaquil up through Quito and on into Columbia. But if you look at the accompanying maps, you'll see faults that run north to south throughout the Andes, including one that passes near Loja (map 2).

Ecuador experiences about 1-2 tremors each day somewhere in the country. Most are of small magnitude and go unnoticed by the population - only monitoring sensors record them. Generally, quakes need to be of magnitude 4.0 or higher to be really felt, or they need to be located very close to population centers. Temblars (tremors) of 4.0 or higher are more common on or near the coast, or north of Cuenca. It is rare for an epicenter to be in, or close to, the city of Loja.

Fault Lines (in black) near Loja City, Map 2
That said, Loja does occasionally feel some rolling from larger quakes that happen at a distance. Most recently (May 2019) there was a magnitude 8.0 in northern Peru. Located several hundred miles away, Loja still felt enough rolling to wake citizens and turn them out into the streets. However, no damage was noted inside the city.

Historically, Loja had significant damage from three quakes - one circa 1640, another in 1838 and then again in 1867. Presumably, the degree of damage was due not only to the size or proximity of the quakes but also due to antique construction methods. Today, the municipality is constantly reviewing and upgrading the building codes to protect people from any potentially large shaker in the future. See my blog post about construction in Loja for more.

The point is that Loja is one of the safer cities in Ecuador geologically. The country's active volcanoes are all in the northern Andes, and we are certainly well protected from coastal tsunamis!

Come for a visit, or come to settle and stay. You'll probably feel more vibrations from a rocking musical performance than an earthquake.

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