OREGON STATE UNIVERSITY

Happy 33rd Birthday Puʻu ʻŌʻō !

If you haven’t heard the news already, the current eruption at Puʻu ʻŌʻō ( an eastern flank eruption of Kīlauea volcano, Hawai`i, USA) celebrated its 33rd year anniversary. Puʻu ʻŌʻō in native Hawaiian means “hill of a digging stick”.

 

Kilauea map

Figure: Map of Puʻu ʻŌʻō in relation to Kīlauea on the Big Island, Hawai`i.(by Johnson, 2000)

 

This eruption started in 1983, on the 3 of January, and as such is the longest-lived rift eruption of the past two centuries. When the eruption first started, it was a series of fissures, 7km long, that split open the ground, in a remote forest northeast of the main crater on Kīlauea, Halemau`mau, along what is now known as the East Rift Zone.

 

puuoo

Figure: Eruption at Puʻu ʻŌʻō when it first started, as seen in September 1983. (by J.D. Griggs)

 

Within six months, the curtain of lava fountains had localized to one vent. At this vent, a spatter and cinder cone has developed. The morphology of this cone has changed over time, due to the waxing and waning of the volume erupted over time, but the eruption itself does not appear to be ending any time soon.

 

puuoo cones

Figure: Changing morphology of the Puʻu ʻŌʻō cone. (from NASA's Virtually Hawaii as depicted in article)

 

The ongoing eruption has been focused there except for a period of 5 years between 1986 and 1992, where it moved 3 km down the rift. Because of it being such a long lived eruption, it was split into several episodes, with each episode spanning the length of time the eruption was active on the surface. Since 2011, after Episode 55, the Hawaiian Volcano Observatory (HVO) stopped using this terminology. Now, if you wanted to see a review of the eruption of this time, HVO has split it into 5 stages, as seen on their website.

 

flows

Figure: Map of lava flows from Puʻu ʻŌʻō divided by episodes and stages of the eruption. (by Orr, 2011)

 

Since the start of the Puʻu ʻŌʻō eruption, around 120 square kilometers of ground has been covered by the flow, and burying over 200 homes and almost 15 km of highway in 35 m depth of lava. The homes in question belong to the town of Kalapana, and the highway buried was the coastal highway that used to provide passage around the Big Island. The interesting thing is that despite the ground and homes that have been made useless because of the lava flows, the flows themselves have created about 500 acres of new land to the southern coast of the Big Island.

 

The eruption has been well studied, both from its physical and geochemical aspects because of the length of the eruption and relative ease of access to the lava flows. The eruption at Puʻu ʻŌʻō is linked to the eruption at Halemau`mau by the underground fissure systems, tied to the magma reservoir below Kīlauea. This process is still being studied and how the eruption at Halemau`mau is affecting the eruption at Puʻu ʻŌʻō is still being observed.

 

cutaway

Figure: A theorized connection between Puʻu ʻŌʻō and Kīlauea through the underground fissure systems. (by J. Johnson)

 

Other discoveries from the study of the Puʻu ʻŌʻō eruption include the ability to predict lava flow pathways! Through field sampling, monitoring of flows through cameras and seismic stations, HVO and their counterparts have managed to create programs that predict where the lava will flow. Of course, sometimes the eruption doesn’t act the way it should, but this only adds to the data collection to help build our understanding of volcano processes. Monitoring the eruption has also provided a look into Kīlauea’s explosive past, from the detailed field mapping and sampling of sequences near the summit and older lava flows.

 

current

Figure: Recent lava flow from Puʻu ʻŌʻō from the sky. (by USGS/HVO)

 

The eruption at Puʻu ʻŌʻō is definitely something to be on the constant look out for. Scientists are learning new things every day from this amazing and beautiful eruption, and it is definitely a force of nature to be reckoned with. If you can’t visit Puʻu ʻŌʻō and Kīlauea yourself, don’t worry! HVO has set up a series of webcams with the best views of the Puʻu ʻŌʻō eruption and lava flows, so you can see the eruption for yourself! Check out the link here.

 

There are several good summaries of the Puʻu ʻŌʻō eruption, and here is a particularly good one that reviews the last 33 years.

If you want to learn more about Kīlauea, check out this link

 

Happy Birthday Puʻu ʻŌʻō!