When the Ground Trembles

Earthquakes have been a hot subject over the last couple months around here.

A seismic sensor made from three Honeywell QA-1400 accelerometers
A seismic sensor made from three Honeywell QA-1400 accelerometers
We live on an island that regularly shakes a bit, the consequence of living with active volcanoes. Obviously this has implications for the great telescopes atop Mauna Kea, every once in a while we experience an earthquake with the potential to cause damage.

The ongoing collapse of the summit caldera on Kilauea has been generating a daily five point something earthquake. While not powerful enough to damage the facility, these events do show up in the data each night, bumping the telescope, disturbing the tracking, and occasionally ruining an exposure.

USGS Earthquake Map for May 6, 2018
USGS Earthquake Map for May 6, 2018
Along with at least one strong earthquake, there are well over five hundred small quakes occurring daily as the eruption continues and Kilauea Caldera continues to subside.

Continue reading “When the Ground Trembles”

Please Define Normal

We are now more than two months into this new eruption from Kilauea. Two months ago the fissures opened in the Leilani Estates subdivision and homes began to burn.

Fissure 8 Lava Fountain
The lava fountain at fissure 8 in Leilani Estates throwing lava hundreds of feet in the air on June 4th, 2018
For two months this slow motion catastrophe has continued. While a major earthquake may be over in minutes, or a hurricane over in a few days, this eruption just goes on. For the folks in lower Puna the lava continues to destroy homes and disrupt lives.

For those of us outside the eruption zone things are not quite as immediate. We read the daily news, peruse images of helicopter overflights each morning, and wonder when it will be over.

The multiple county civil defense status reports and various emergency alerts that pop up on our phones each day provide current information… A bit of the Mamalahoa Highway has collapsed in Volcano Village with a one lane restriction, the road to Kalapana has re-opened, there is no tsunami threat from that last 5.4 magnitude earthquake.

July 7, 2018 Summit Collapse Earthquake
A plot of the July 7, 2018 summit collapse earthquake as recorded by an accelerometer in the Keck Observatory foundation
Every day is punctuated by a magnitude five point something earthquake. These summit collapse events have become very regular. You can guess when they will occur as the frequency of small quakes increase around the caldera.

For the most part these events pass unnoticed by much of the island. The volcano area gets shaken up pretty well, but these fifth magnitude quakes are often not felt very far beyond that.

On the summit of Mauna Kea these daily quakes often do disturb the telescopes at night, bumping the tracking and ruining exposures, but otherwise too weak to cause any damage to the facilities.

Hualālai peeks over a thick layer of volcanic smog, or vog
Hualālai peeks over a thick layer of volcanic smog, or vog
The most significant island wide impact has been the vog, wreathing the island in a sulfurous haze. Sulfur dioxide pours from the active vents, mixes with water in the air and forms a thick brown grey haze.

When the vog is bad you not only see it, you smell the sulfur, it irritates eyes and nasal passages. Fire and brimstone reaches out to touch us all.

While the vog makes for spectacular sunsets, the vog can also be thick enough to curtail outside activity. A day like today, with brisk trade-winds to clear it away, is a welcome relief.

Fissure 8 Lava Fountain
The lava fountain at fissure 8 rising about 250 feet as this Kiluaea eruption continues unabated.
Opportunities to legally witness this eruption are few, authorities have been enforcing the evacuation area increasingly strictly. Legal options are the fly or float to the eruption. Deb and I chose to fly a month ago, a helicopter flight I am sure we will remember for a lifetime.

I have not attempted to go to photograph the lava river, despite a very strong desire to do so. The county and state have repeatedly talked about opening a lava viewing area. while there is a great deal of pressure from the community, so far nothing has materialized.

We are so ready for this eruption to be over.

Given the collapse of the summit caldera and the enormous volume of lava emitted so far, it may be possible that when this is over there will be no further eruption for a while. It may take a while for the volcano to recharge, perhaps a year or two. Will we return to the pattern of intermittent eruptions that was seen through much of the 20th century?

Stray

Arriving back to the house late I realize something is under the lanai. A loud rustling of leaves and a jingle betrays something bigger than one of the neighborhood stray cats.

New Year Fireworks
Neighborhood fireworks signal the arrival of 2015
I pull the flashlight from my pocket to start looking about when a dog emerges. A very friendly shepherd mix appears in the flashlight beam. Deb reminds me that this is the Fourth of July, and that this dog may be panicked by the fireworks that are still crackling through the neighborhood.

Fortunately this dog has good tags, one tag includes an address just a few blocks away. Deb gets me a leash while I hold the collar, scratch between the ears, and make friends.

A nice evening for a stroll. This stray dog is very well behaved, walking alongside me up the street. A few fireworks are still going off and I worry about the dog bolting again. My guess is that some human accompaniment is all that was needed.

As I arrive in the cul-de-sac indicated on Google maps I see five houses, which one? I did not need to pull out the flashlight to check the addresses, the dog tugs me straight for one particular front door. Sure enough, the same address that is on the tag.

It is the right house?

Yes. I got hugged.