Thursday, July 17, 2014

Kona Infrasound Event 140717

UPDATE: Event report is up on the ISLA blog page (this page is under development at the moment but we are trying to get all our event reports posted as we write them)

At 4:00 pm HST a loud noise was heard in the Kahalu-Keauhou area of Kona on the Big Island.

ISLA has received three accounts that are as follows:

1)  "a big bang that shook the ground"

2) "HUGE BANG that scared all the animals followed by jet noise. It sounded like it was right overhead" - Donkey Mill Area

3) "It was super loud. Right over Kahalu'u. I think it was a jet. It was so loud. I talked to people at kta and they said the whole building shook" - Kahalu'u beach park area

The signal was recorded at IMS station I59US in Kona. Array processing was done to determine the back azimuth of the signal.
Final back azimuth as calculated using PMCC4.15, which crosses the coast at Kahalu'u Beach Park

direction of the signal as calculated using array processing

The signal as recorded at station I59US 
This post will be updated later with any new information and more detailed analysis. Any other observations from witnesses are appreciated! Hopefully by the time of the next update the source will be known. 

Wednesday, March 19, 2014

Happy 6th Birthday Halema'uma'u Eruption!

Today the March 19, 2008 eruption at Halema'uma'u turns 6! The eruption in the Halema'uma'u crater began with a small explosive event, and continues today with a beautiful lava lake. In honor of this birthday we at the lab have put together a sound file of 24 hrs of infrasound data mapped into the audible range for your listening pleasure (3/18/14 19:00UTC - 3/19/14 19:00 UTC).

Technical information: These data were recorded by a C50a ~ 7 km from the vent. The data were then bandpass filtered between 0.3 to 10 Hz before being sped up ~1,000x to map into the audible range. The above image is the result of our automated processes (still in development at this time) for the same time period.  

Here at the lab we love to check in on the volcano, and HVO has an amazing array of products that help us keep up to date on what is happening. At the time of writing this is the image from the webcam at HVO:

The image used for the track is also the overlook thermal camera image at time of writing. There is also currently a deflationary event going on at the summit according to the daily eruption update.

Happy Birthday Halema'uma'u eruption and thank you!