Watching Mauna Loa

Being an inveterate volcano watcher, I have not only been watching the new flow on Kilauea, but keeping a wary eye on Mauna Loa as well. The USGS has steadily been increasing the alert level on this largest of the Hawaiian volcanoes over the last year.

On this unstable rock we live, we get a fair number of earthquakes. Of course not every bump you feel is seismic, sometimes it is just a big truck on the highway. You look on the USGS Recent Earthquakes page anyway, just to see what it was. Not this time, must have been a truck. While I have the page loaded I look about… Wait? What is that cluster on the NW flank of Mauna Loa? I do not remember seeing that before!

For the last year or more there has been a steady cluster of small earthquakes just to the southwest of the main caldera. This notable cluster is usually visible when you stop by the earthquake page and indicates magma motion below the summit. It is a big part of why the USGS has upped the advisory level. The cluster on the west flank looks new to me, a lot of small quakes, some deep, some as shallow as 600m.

I am sure someone over at the USGS is looking at the same cluster and asking the same questions. Maybe they have better answers, but they have not published anything yet. Maybe, like so many times before this cluster will fade away, not to appear again. It is however a reminder that magma is moving down there, the mountain is swelling, someday she will erupt again.

Today I will be driving up and down the mountain. I know I will be looking across the saddle at the looking bulk of Mauna Loa and wondering for the thousandth time. Will I see an eruption from her during my years on island?

HVO Earthquakes 15July2016
HVO earthquake plot for 15July2016

The Trail to Emesine Cave

There are few open paths to trail ride on this island, a place where landowners gate every side road and jealously guard any access. There are a number of exceptions, but you have to look to find them. One such is a power line road off of Saddle Road. The power line is gone now, the stumps of poles remain where they were sawn down years ago. The road runs arrow straight across the landscape, now serving forestry crews, pig hunters and hikers. Enough traffic traverses the path the keep it clear of growth. Here is a glimpse of natural Hawai’i, where invasive species are relatively few and the calls of native birds echo amongst the ‘Ōhi’a.

Preparing for the Trail
Getting ready to set down the trail to Emesine Cave
While I had hiked the trail a couple years past, cycling gave me a whole new appreciation for the ruggedness of this old power line road. Whole sections were cobble that shifted and rolled under the knobby tires. I got a lot of rock dodging practice, carefully choosing where to run my tires through the rough lava. In the end I was forced to walk the bike along whole lengths of the route where the loose cobble was simply too dangerous to ride. The sections among more recent flows were the rough parts where the road was simply bulldozed through the rock.

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