How can one resist clicking on something called a “ShakeMap”? The lovely, simple image above showed up on a quick search of United States Geological Survey (USGS) information about the recent earthquake in Hawai’i. I’m left curious about the little circles and triangles that dot the map—presumably they represent measurements of some sort, but I can find nothing to corroborate that hypothesis. Like any good netizen, I read the figure’s accompanying text, and although it told me quite a bit about the purpose of a “ShakeMap,” it didn’t reveal the purpose of the tiny icons. Furthermore, they seem to have shifted from when I looked at the map earlier in the day. Fascinating but opaque.

It’s also interesting to compare the “decorated” version with the “bare” version offered up on the site. The former includes a graphical scale in kilometers (nice enough) while the latter features latitude and longitude markings along the edges. A puzzlingly minute difference. But I find it heartening that both include some sense of scale! Seems like geologists are well ahead of planetary scientists on this count.