Activity slows further at Kīlauea, returning to near background levels

If activity at Kīlauea is any indication, it seems Pele is enjoying an amusement park while on vacation.

The Hawaiian volcano goddess must be a fan of at least smaller roller coasters because of the ups and downs the Big Island volcano has seen since the end of April. Her most recent ride continues, it’s just coasting along the rails more calmly.

Kīlauea is still shaking and showing signs of unrest beneath the upper East Rift Zone, summit and south caldera regions. During the past day, however, earthquake activity and ground deformation further slowed.

The number of quakes in all three areas are again at background levels as of shortly before 8 a.m. today. Earthquake depths have averaged between 0.6 and 1.9 miles beneath the surface, and magnitudes have been less than 2.

Despite slowing, ground deformation continues beneath Halemaʻumaʻu Crater inside the caldera and in the south caldera region.

The Uēkahuna tiltmeter northwest of the summit recorded minor inflation during the past day. The Sand Hill tiltmeter southwest of the summit also showed minor uplift.

Seismicity in Kilauea’s Southwest Rift Zone is relatively low outside the summit region.

Sulfur dioxide gas emission rates remain low. An emission rate of about 61 tonnes per day was recorded May 21.

While earthquake rates and deformation have slowed beneath Kīlauea, based on activity during the past several weeks, rates could increase again at any time.

It is not possible to say whether the recent heightened unrest and fluctuations in activity will lead to an intrusion or eruption in the near future or simply continue as unrest.

Changes in the character and location of unrest can occur quickly, as can the potential for an eruption.

Magma has been pressurizing the system beneath the south caldera region and Halemaʻumaʻu for several weeks, causing sesimic activity in the upper East Rift Zone and south of the caldera.

A period of heightened unrest began April 27. The number of earthquakes peaked at an average 360 per day by the end of the month, with more than 1,500 recorded beneath the upper East Rift Zone and southern end of the caldera throughout a 5-day period from April 27 to May 1.

That spike in activity lasted until early this month when the number of quakes and ground deformation returned to levels similar to those prior to the period of heightened unrest.

Since then, seismicity and deformation have seesawed, increasing and decreasing.

An information statement summarizing the spike in activity can be found online.

Kīlauea’s Volcano Alert Level remains at Advisory. It’s aviation color code also is unchanged at yellow.

The Hawaiian Volcano Observatory will continue to provide daily updates while unrest continues under the volcano. The agency is closely monitoring Kīlauea for signs of increasing activity.

Should volcanic activity change significantly, a volcanic activity notice will be issued.

For more information, visit the Hawaiian Volcano Observatory website or email to askHVO@usgs.gov. To get the Kīlauea activity summary, click here or call 808-967-8862.