Blast Map

http://vannizhang.github.io/blasts-viz-app/

Here are recorded seismic events since 1963 that have been deemed to be man made. One benefit of covering the globe in a network of seismic sensors to detect earthquake and volcanic activity, is that you also tend to pick up the rumblings of a not-so-natural source.

PNW — Blast Map is an app that lets you browse around in place and time for a filtered look at a history of massive explosions. Here is a closer look at the rumbling mines of the Pacific Northwest.

What sorts of explosions could be big enough to register on earthquake monitors? Pretty much two activities: quarry blasts and nuclear testing, according to the Northern California Earthquake Data Center (the same diligent institution that provided the data for this), who aggregate this data from dozens of global seismic networks.

Some Interesting Clusters
There is a sort of magic that happens when you push data into information -and the best way to do that is to show where and when something happens. I was used to seeing this as a spreadsheet, but when those points manifested as geographic coordinates and a paired timeline, I saw patterns and clusters that sent me down all sorts of Wikipedia rabbit holes. Get ready to live.

Of course it’s really tempting to first take a look at the very biggest blasts on record. Many, but not all, of these big ones are underground or surface nuclear tests. This data starts in 1963, which happens to coincide with the Partial Test Ban Treaty -when nuclear testing was restricted to underground (over fallout concerns of atmospheric and oceanic testing).
Notice the precipitous decline in the early nineties, presumably due to the fall of the Soviet Union in 1991 and the Comprehensive Nuclear-Test-Ban-Treaty in 1996.

ReallyBig — The largest of the human-caused seismic activity over a half century.

For what it’s worth, here is a look at all the nuclear-strength blasts since 1996, including the tense days of the India/Pakistan testing race and also some activity from North Korea.

Historically, there are a few (in)famous long-term testing sites.

The Nevada Test Site is a well-documented constellation of testing facilities and craters. America’s Nuclear Moonscape goes into rich detail about the site and its history. Here‘s a link to it in the Blast Map.

The Soviet counterpart to the Nevada Test Site, is the “Semipalatinsk Polygon.” It’s a region in the steppes of Kazakhstan where, over decades, all sorts of testing took place, ending abruptly in 1990. Visit the Blast Map to explore it, and read about it here.

You can see target symbols etched into the landscape nearby some blast points. And there is also a radioactive crater lake named Lake Chagan, caused when a river filled it up (visit the map, or read about it here).

But, most of the points in this data set are from quarry explosions. The time chart shows some sites with interesting patterns and histories. One of the most dramatic, and sustained, is an operation near Centralia Washington. If you zoom in on a mining cluster, then pan south, you can see the operation migrate through time. Likewise, if you walk the timeline filter through time chunks, you can see a meandering movement as veins play out.

How and Why Was This Map Made?
This started when I was looking at a CSV table of these blasts, and noticed a steep decline that corresponded with the breakup of the Soviet Union. I showed cohort Jinnan Zhang and we quickly cooked up a scheme to map and chart them so we could explore it. We spent some evenings and spare cycles collaborating and revising. When it comes to maps, we just can’t help ourselves.

Jinnan was interested in exploring the integration of D3 components with the ArcGIS API for JavaScript. As you navigate the map, updated values are sent to the chart. And as you filter the chart, updated values are sent to the map. The blasts are the natural intersection of the two views.

I was interested in trying out the ability to create custom vector basemap cartography, somewhat under the influence of WOPR. Shall we play a game? And I’ve always been keen to let maps and charts talk to each other in a natural manner -it’s just what the universe wants. This was a chance for us to totally nerd out on some data.

Data