Kīlauea’s Fissures Pour Out Lava While Merapi Continues to Cause Concern

By Erik Klemetti | May 24, 2018 8:58 pm
Lava fountaining up to 50 meters from Fissure 22 near Leilani Estates on Kīlauea, seen on May 22, 2018. USGS/HVO

Lava fountaining up to 50 meters from Fissure 22 near Leilani Estates on Kīlauea, seen on May 22, 2018. USGS/HVO

With the eruption at Kīlauea dominating the news, I thought it important to highlight the other developing volcanic crisis that is happening right now. Check out that news after we catch up on what’s going on in Hawai’i.


However, what really still has much of the world’s attention is the ongoing lava flows, fountains and explosions (see above and below) from Kīlauea. According to the latest report from the Hawaiian Volcano Observatory, it is the middle of the Leilani Estates fissures that are the most active right now. Some of the lava flows from these fissures are now feeding multiple ocean entries between Pohoiki Bay and MacKenzie State Park (see map below). Be sure to check out the great infrared image of the lava flows taken by Landsat 8 along with USGS video of “methane flames” caused by lava burning vegetation seen the other evening. UPDATE May 25 9:00 AM ET: The U.S. Marines are preparing helicopters in case the last escape route for some communities in the lower Puna gets blocked by lava advancing towards the sea.

Composite satellite thermal image of the Leilani Estates eruptions on Kīlauea, seen on May 22, 2018. USGS/HVO.

Composite satellite thermal image of the Leilani Estates eruptions on Kīlauea, seen on May 22, 2018. USGS/HVO.

Luckily, although there are still a lot of earthquakes happening under the lower East Rift zone, meaning more magma is moving to the Leilani Estates fissures, they don’t seem to be propagating further east. We’ll have to wait and see if that means this eruption is going to establish itself in these middle fissures for the duration. (I would also not recommend trying to move a just-erupted volcanic bomb with your bare hands.)

The question I’ve gotten quite a bit lately is how long this eruption will last and so far, there aren’t a lot of signs that the eruption is close to ending. The eruption of Barðarbunga in Iceland that formed the Holuhraun lavas in 2014-15 lasted for months and ended up spilling over a cubic kilometer of basalt lava from a series of fissures, eventually forming a large central cone that housed an ephemeral lava pond. Now, I’m not saying that this eruption will be that dramatic — Iceland tends to produce much larger basaltic eruptions than anything Kilauea has experienced. However, the timeframe of eruptions like these could be months when looking at Kīlauea’s past and analogous events at volcanoes in similar settings (like Iceland). UPDATE May 25, 9:15 AM ET: The May 25 HVO update mentions that fissures 7 and 21 are now feeding into a small lava pond! This isn’t being fed from below like a lava lake, but rather lava accumulating near the vent and staying hot enough to form a pond.

Check out the progression just over the last few weeks on the lava flows from these fissures:

The explosive eruptions at the summit has continued as well, mostly producing ash plumes that reach 1.5-3 kilometers (5,000-10,000 feet), impacting local communities from all the ash. These blasts will continue as long as the summit deflates and magma drains out towards the lower East Rift zone eruption. A few moderate earthquakes struck the summit area over the past few days as a result of the continuing deflation. Coming back to the Barðarbunga eruption, we saw the same deflation and collapse in the main part of the volcanic system’s caldera while the lava erupted on the periphery. A UAV flight was able to observe the Halema’uma’u crater and see the steaming crater (well, steam mixed with ash).

The USGS also had to remind people that no, Mauna Loa is not erupting. This seems to be a persistent rumor with the activity at Kīlauea, but there is no connection between the two volcanoes that will lead one to start erupting because the other is already doing so. Everything is pretty much normal at Kīlauea’s larger, older cousin. Considering these rumors that want to make the eruption a larger disaster than it is, I’m glad someone made this image to remind us of the scale of events:

If you want to read or watch some more of my observations about these eruptions, check out these articles or TV spots:


Activity at one of Indonesia’s most active and deadly volcanoes of the last century continues to increase. After a steam-driven eruption a few weeks ago (the first in 4 years), the phreatic explosions at Merapi have continued and recent blasts have reached as high as 6,000 meters (~20,000 feet), dusting ash on many communities near the volcano. This also means the ash from these eruptions is a hazard to aircraft flying near Merapi on Java, especially those flying in and out of Yogyakarta. So far, only 660 people have had to evacuate due to the unrest at Merapi, but remember, over 4,000,000 people live within 30 kilometers (~19 miles) of the volcano. To compare that to the eruption at Kīlauea where 8,400 people live the same distance of the volcano. Ash from these explosions can be seen in the Sentinel-2 images in the tweet below.

The last major eruption of Merapi in 2010 killed hundreds of people, so even with the relatively small eruptions, the PVMBG has declared a 3-kilometer exclusion zone around the volcano. The Institute for Research and Technology Development of Geological Disaster (BPPTKG) in Yogyakarta has stated that they think the volcano is “entering a new magmatic phase” but cautions that there are no signs so far that this eruptive phase will be as bad at the devastating 2010 eruptions. I interpret this as meaning that these steam-driven blasts are not merely due to water percolating into the volcano, but rather new magma rising up under the volcano.

CATEGORIZED UNDER: Rocky Planet, Science, Science Blogs
  • Thomas S

    I’m curious about the use of the word “magmatic” in the post by the Institute for Research and Technology Development of Geological Disaster (BPPTKG) in Yogyakarta – the definition I find for the term is

    “The molten rock material that originates under the Earth’s crust and forms igneous rock when it has cooled. When magma cools and solidifies beneath the Earth’s surface, it forms what are known as intrusive rocks. When it reaches the Earth’s surface, it flows out as lava and forms extrusive (or volcanic) rocks.”

    … and it sounds like everything is part of the same phase, not a new phase, what is a beginning or a end phase?

    • leanne wiberg

      Perhaps simply UNDERSTANDING the concept was your main goal in posting your comment. IF SO, read on. Igneous rock can have two origins. Because it has two ways of forming, it has two names depending on its “origin story”. Igneous rock of INTRUSIVE origin is rock formed UNDER the earth’s surface as magma (which never made it to the earth’s surface) cooled underground. We only see intrusive rocks ON the land in places where they are revealed because the rock and soil covering them been removed by erosion. Igneous rock of EXTRUSIVE origin is rock AT the earth’s surface which formed as magma (which succeeded in making it to the earth’s surface because it was under enough pressure to be pushed out) cooled. We see extrusive rocks on the surface because the ARE part of the earth’s surface in those places near volcanoes. Lava is the name for is magma which has made it to the earth’s surface. You can see lava in images and with your own eyes; you could never see magma.

      • Thomas S

        Thank you.

        So how do we define a new phase of magmatic activity?

        • leanne wiberg

          I’m assuming the phrase “magmatic activity” relates to how the magma underground is moving, or not moving, as the case may be. As it rises because of pressures around and below it, the molten mass interacts with reserves of groundwater during its ascent. It also interacts with the rocks that it is melting. As the magma relocates to a position higher up and nearer the surface, it interacts with its new enclosing environment. Its physical state and its chemical states are altered as reacts to the new surroundings. However, these changes don’t happen all at once. I’m assuming that the different “phases” referred to relate to the physical and chemical stages in the molten mass over time. I’m an astrogeologist who did a short stint working with vulcanologists and who had a class in vulcanology over 40 years ago. Hopefully, someone with a more recent work history with volcanoes will chime in here to tell me whether I’ve explained things adequately, or whether I’m off the mark. Regards!

  • http://www.mazepath.com/uncleal/EquivPrinFail.pdf Uncle Al

    When the lava ocean quenches, do we get obsidian?

    • Chris DeVries

      No. It typically forms black sand, which is shards of basaltic glass called tachylyte. Obsidian is a material that is granitic/rhyolitic in composition, and it usually forms on continents, at subduction zones and divergent boundaries, in places where magma can sit around underground and differentiate, losing the iron and magnesium that are in most juvenile magmas (via Bowen’s Reaction Series), AND in places where existing rocks of granitic composition can be re-melted by large bodies of magma moving adjacent to them. If it then erupts and is quickly quenched, it will form the volcanic glass known as obsidian.

      While I am unaware of any obsidian being found ever on the island of Hawaii, it’s not technically impossible. The volcanoes’ magma start out as basalt, but right here on this blog (last post) you can read about andesite and dacite being found at Kilauea (andesite towards the beginning of the current eruption, dacite underground that was encountered during drilling geothermal wells). So under the right conditions, rhyolitic magma could form in Hawaii. Whether it erupts or not is another thing though, and whether it erupts under the right conditions to create obsidian is a further wrinkle.

      There are other volcanic glasses of various morphology formed in Hawaii, from Pele’s hair and tears, to the shards of glass found in laze plumes, to the basaltic equivalent of pumice – reticulite. I’m not certain if they can all be called tachylite or if that term is reserved for glass associated with fast-cooling bodies of basalt (flows and ejecta). I understand the confusion about obsidian vs. basaltic glasses though – they can look remarkably similar – but there is a big difference (besides their composition): obsidian looks black, but if you break a shard off and find a portion that is less than a 5-10 mm wide, you’ll notice it is pretty transparent (unless it has minerals within it like iron oxides like hematite that completely block light transmission – certain types of obsidian do). Tachylite is opaque until you get it much much thinner – it is crowded with magnetite crystals and frequently bubbles that block the passage of light much more effectively than most obsidian.

      • http://www.mazepath.com/uncleal/EquivPrinFail.pdf Uncle Al

        Thank you. “mafic igneous rock that is decomposable by acids and readily fusible” There goes Hawai’ian carriage trade custom labware.


Rocky Planet

Rocky Planet covers all the geologic events that made and will continue to shape our planet. From volcanoes to earthquakes to gold to oceans to other solar systems, I discuss what is intriguing and illuminating about the rocks beneath our feet and above our heads. Ever wonder what volcanoes are erupting? How tsunamis form and where? What rocks can tell us about ancient environments? How the Earth might change in the future? You'll find these answers and more on Rocky Planet.

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