‘How Two Big Earthquakes Triggered 16,000 More in Southern California’

The work entitled ‘How Two Big Earthquakes Triggered 16,000 More in Southern California’ has been awarded the prize of Best Map (Digital). The work was published in The New York Times (USA) and the graphics editor behind the piece, Derek Watkins, shares with us some of what went in to creating the piece and the challenges they faced.

Could you briefly explain the idea of the story? 

Two big earthquakes shook California near the Mojave Desert last July. When I looked at USGS earthquake data to make a simple locator map, I saw that the two were actually part of a swarm of thousands of earthquakes, each with a chance to be large. I didn’t know that was how earthquakes worked, and thought readers might find it interesting. So we put together this visual story to explain it.


What was the process of working on the graphic? 

First I sketched the data in an animated chart and map right next to each other, to see what the most interesting visual patterns might be. Then, I called scientists and asked them to explain to me why those patterns looked the way they did. Once I understood what the important parts of the story were, we adjusted the graphics to clarify those points, and I wrote a draft connecting the visuals to each other.

Sketching annotations for the chart:

Sketching the progression of the story:

What has been the challenge of this story? 

The way that scientists calculate earthquake probabilities is nuanced, and some parts of it aren’t very intuitive. It was a challenge to explain what was happening in a clear way without oversimplifying the science. Visually, it was difficult to find the timing of the animations that would draw readers’ attention to the important parts of the graphics without feeling frantic.

Derek Watkins

What do you think?