Map showing the geologic echelon loci "trends" of the "Kea" and "Loa" Hawaiian volcanoes.
USGS
1987
<a rel="nofollow" class="external free" href="https://pubs.usgs.gov/pp/1987/1350/pp1350_vol1.pdf">http://pubs.usgs.gov/pp/1987/1350/pp1350_vol1.pdf</a>