Comparing siesmic tremor with surface events

Three events late May 2018 were added to the graph of seismic data. Time for this graph was adjusted so data points represent the end of a 6 hour average instead of the start of a six hour period.


The best time stamp for the opening of Fissure 24 I was able to find was 10 am the morning of May 27, 2018. Fissure 24 produced a very large flow and this may account for the dip in seismic tremor level.

Why finding volcano tremor activity level is important

Looking at an erupting volcano:
Quick have a look at this seismograph. What time was the volcanic tremor the highest? Is it increasing? The answers are kind of important. There is a geothermal plant right next to the lava flow.

Average seismic tremor level for East Rift Zone

The following graph is an overview of the average seismic tremor level for the past few days for 4 different seismographs around Leilani Estates, and Kapoho on the slope of Kilauea Volcano. The last update was on May 28th, 2018 at 6pm HST.

Wow! Data is following a neat pattern showing high activity then low. Each time the low activity has been lower. Further, the time between cycles is becoming greater.

Notice the upswing at KLUD is so much stronger than what is seen now at ERZ1 & 2. Suspect that is due to so much fissure being open uprift of those two stations.

Time to make my YouTube video for people too busy to read this blog.

Disclaimers:  The six hour data averages are snapshots. This means that peak highs and lows may actually be lower and not as in phase as this graph represents. To capture a moving average more closely, I would have to stitch the data together and then measure the average on shorter intervals.

Standard objectives

The volcano tremor activity level objectives include:

Measurement technique overview

Steps include capturing seismograph images, adding a scale to the left of the page, and then converting it into a black and white image.

Getting started: Download free software ImageJ

Free software from the NIH helps establish a repeatable method so anyone with a computer and internet connection can determine volcano tremor activity level.

Finding good seismic data for volcano tremors

The USGS publishes live data from seismographs on their website. For volcanoes in the USA. Do a google search if you are looking for seismograph outputs in other countries. Here is a sample search for Japan.

Downloading your seismic data and creating reference lines

Now that you found sources of seismic data right click on the image and select Save Image As...

I create a directory for each set of seismic graphics I down load.

Processing the seismograph using ImageJ

Find the program ImageJ you installed on your computer. I suggest making a link on your desktop since it may not appear in your start menu.

Elimination of the baseline: How to find background "noise"

A seismograph generates pixels on the page simply by drawing a line across the page. Even if there is 0 tremor, there still would be a line and the ImageJ software will count pixels. Further, the page itself contains division lines for each minute and you may also be measuring the division lines between rows. Subtraction of these pixels is important since they do not represent tremors.

Listric faults: Can they erupt and become a rift zone?

Kilauea Volcano is riddled with cracks and fault lines. Only a few of these cracks actively produce lava flows. When a fault line produces lava is called a "rift zone".  In May 2018, one crack caught my attention owing to earthquake activity. This crack is South of, and parallel to, the  East Rift Zone. The big question is whether lava will erupt from this area.

Comparing two 6-hour periods of tremor: Same seismograph

Now that you have your ImageJ software installed, answer this question:
On Kilauea Volcano there is a seismograph near a geothermal plant at risk.
For May 22, and 23 2018 were the tremors increasing or decreasing?  Use the two 6-hour snapshots provided.

Compare two different seismographs for same 6 hour period

On the slope of Kilauea are two seismographs that are relatively close together. One is positioned to the North and one to the South of a line where lava may erupt from the ground and inundate the neighborhood of Kapoho. On May 23, 2018 which seismograph was recording greater activity?

File naming convention.

Keeping track of files and plotting results requires a consistent naming convention for files.

About the author and using materials from this blog

Philip Maise is an amateur and none of his work is checked by "professionals". Further, Maise makes no claims or warranties that his methods are definitive proof that a lava flow is or isn't about to occur. Always consult local government authorities when making critical decisions regarding potential lava flows.