Photos by Dr. Edward Kohut, all rights reserved, used by permission, 2009
Many times people think that volcanic eruptions affect the economy through the destruction inflicted upon the landscape during an eruption: lahars and pyroclastic flows destroying bridges and homes, ash ruining crops and water, lava flows overunning communities. However, in Hawai’i, a new effect of volcanism has been seen in the agriculture of the state. The volcanic fog – or “vog” as its called – has been causing major problems with farms on the Big Island of Hawai’i. Since the new activity at Halemaumau (see above) began last year, Kilaeua has been spewing much larger volumes (2-4 times more) of volcanic gases such as sulfur dioxide, carbon dioxide, water and carbon monoxide than in previous years. These gases form a brown fog that is caustic to most animals and plants. The sulfur dioxide, in particular, has caused many crops to fail thanks to the production of sulfuric acid with the sulfur dioxide interacts with water – think of it as a very concentrated version of “acid rain” that is seen in the eastern United States.
The solution to this would either be to build “vog-proof” air-filtering greenhouses or planting a limited set of plants that seem to withstand the effects of the vog. Alternately, one can hope that the gas emissions from Kilaeau will return to lower levels, allowing for the plants to survive. In any of these cases, the growers on the island face a large financial hardship in order to keep their businesses alive in the face of the volcano. This passive destruction of plants by Kilaeua shows how even when a volcano seems to be benign, it can inflict millions of dollars of damage on the local economy.
Lava issuing from the current eruptions at Kilauea have started a third ocean entry (and the second within the Hawai’i Volcanoes National Park). The entry is not as dramatic as some, forming a slow, dripping entry of lava into the ocean (see linked video footage), but every little drip adds a little more land to the big island of Hawai’i.
In some other Hawaiian volcano news, the USGS have also posted a video showing the filling and draining of the lava lake in Halemaumau that started last year. Usually, the crater was surrounded by steam and fumes from the degassing magma, but the thermal camera pierced the veil to show the lava rising and falling within the crater.
For those of you interested in what happens in the realm of submarine volcanism, I can pass on some tidbits I’ve gotten about NW-Rota 1, a submarine volcano in the Mariana Islands (see bathymetry above). Dr. Ed Kohut (Petrogenex), a friend of mine from my days at Oregon State Univ., is currently on a JAMSTEC research cruise in the Mariana Islands, visiting the area about NW Rota-1. He reports:
“We just reached NW-Rota 1. It is still actively erupting. To put that in perspective, it has been observed erupting every time it has been visited since 2003. Today’s actvity is not as vigourous as in past visits, but there are billowing sulfur laden plumes and the summit has increased ~15 meters since the last ROV visit (in ’06?).”
Seems that this seamount continues to chug away under ~500 meters of seawater. It is most famous for the 2004 eruption that coated an ROV that visited the volcano with ash and molten sulfur during an eruption (all under water). Below is a short video from a 2006 research cruise of the vigorous behavior at the vent called “Brimstone Pit”, which produced the 2004 eruption. You can clearly see the ash, rock and gases being ejected from the vent, all under half a kilometer of seawater!
One of the more impressive areas I visited while in New Zealand was the Waimangu Valley near Mt. Tarawera (above). The valley itself was created by blast explosions (phreatic explosions) during the 1886 eruption of Mt. Tarawera. These eruptions cut right down the axis of the rhyolite domes (most of which erupted ~1305 A.D.) and extended off the volcanic edifice to form the valley to the west of the volcano. In the valley, no juvenile lava was erupted, instead explosions carved out large pits that formed the Waimangu Valley and today the valley is filled with lakes and thermal features (below).
The 1886 eruption at Tarawera was not large by any means, erupting only ~0.7 cubic kilometers of basalt (compare that with the 1305 Kaharoa Rhyolite from Tarawera that erupted 5 cubic kilometers). However, hundreds of Maori villagers died during the eruption and basaltic tephra can be found all over the area north of Tarawera into the Bay of Plenty. Yet, only about a century later, most of the destruction caused by the eruption has been erased by vegetation. Compare the photo of the valley just after the eruption (top) to the one I took in January of 2009 (bottom) to see how things have recovered.
Waimangu Valley, 1886
Waimangu Valley, 2009
Volcanoes are truly destructive, but still just a flash in the pan for most earth processes.
I made it back from New Zealand yesterday after spending the last two weeks looking at some of the most remarkable volcanic landscapes you could imagine. I’ll add more detail soon for those of you interested in the volcanism of the North Island, but I’ll leave you with a picture of yours truly in from of Ngauruhoe (a.k.a Mt. Doom) along the Tongariro Crossing. The volcano last erupted in 1977 and it considering the youngest vent of Tongariro. Ngauruhoe has had >60 eruptions over the last 150 years.
Although this news isn’t as threatening as the title of the article implies: HAWAII LAVA FLOW NEARS NATIONAL PARK, it is still some news as it could be the first lava flow to cross into the park in over a lava. The flow itself is headed towards what is called the “Waikupanaha ocean entry” on the southeast side of the island. The lava flow has about one mile to go before it reaches the Pacific Ocean, but it has travelled several hundred feet (maybe 100 meters) over the last 10 days according to Park Rangers and USGS geologists monitoring the flow’s progress.
Of course, compared to your average pyroclastic flow or lahar, traveling at tens to hundreds kilometers per hour, tracking this lava flow is a little bit like watching paint dry (except, of course, it is lava). It shows the whole different level of volcanic hazard presented by Hawaiian volcanism versus Plinian (explosive) volcanism, where the level of concern at the park can be summed up with “Our idea is not to control and prevent. Our idea is to educate.”
A quick update from Reunion Island on this fairly slow week, volcanically speaking:
“After permanent unrest with daily 30 to 100 seismic events, Piton de
la Fournaise volcano erupted again on Thursday November 27, 2008 at
11h50. The eruption is situated on the west side within the Dolomieu
crater at the same vent as the September 21 eruption and can probably
be considered as a second phase of the later.”
This comes from the Observatoire Volcanologique du Piton de la Fournaise (OVPF – link in French). Piton de la Fournaise is a shield volcano on Reunion Island that sees frequent basaltic eruptions, like many hotspot-related oceanic island volcanoes (such as Hawai’i).
Sounds like we’re beginning to get a better idea of what is erupting in Ethiopia. Ghezahegn Yirgu, a geologist at Addis Ababa University, reports that Dalla Filla Dalaffilla Volcano is the source of the eruption. Again, the eruption is being characterized as “lava flows” rather than an explosive eruption, which may be surprising considering the amount of volcanic gases being released (see Boris Bechnke’s highly useful comment). However, some mostly effusive eruptions have released a lot of volcanic gases in the past – see Laki, Iceland in 1783 – so a preponderance of flows at Dalla Filla Dalaffilla would not be shocking.
Now, there is surprisingly little information I can find about Dalla Filla – in fact, it doesn’t even appear in the GVP database or, for that matter, almost anywhere on the internet. The volcano is located, according to the article linked above, about 20 km north of Erta Ale, so it is in a region of active East African Rift volcanism. The map above (from the USGS) shows all the volcanoes in the area that have known eruptions since 1800, so unless Dalla Filla is being confused with Dallol, it might be the first eruption of the volcano in quite some time. I’ll update once I can find more information on Dalla Filla (and feel free to comment here if you know more than I).
REVISED (11/6/08): Apparently, the volcano in question is Dalaffilla, which shows up in the GVP website (Thanks Ole and Ron). There isn’t much information on Dalaffilla, except that, surprisingly, it appears to be a silicic volcano. The reports I’ve read so far seem to indicate that lava flows have spread out over a large area, which would suggest a low viscosity (i.e., basaltic) lava. Thanks to the Eruptions readers who dug out some great information.
In one of the most oddly worded articles I’ve seen from the BBC, a lava flow from Erta Ale an unidentified volcano in the Erte Ale range in Ethiopia has erupted a significant amount of lava. The headline states “Ethiopia volcano sets lava record”, which is strange on multiple counts, but mostly because I’m not familiar with any “lava records”, who might keep track of them and what, exactly, this “lava record” is. In fact, they don’t even mention it in the article itself. They do, however, point out that lava from this eruption has covered 300 square kilometers, which is a decent chunk of real estate, but no mention is made of how long it took to do this (or what type of lava, for that matter, but it is likely basalt). So, take this article as you will. The take home message is that Erte Ale a volcano in the Erta Ale range, near Alu, has had a significant eruption with some associated earthquakes to go along with it.
Erta Ale is located on the East African Rift in Ethiopia – part of the Erte Ale Range – and is a fairly active shield volcano that erupts basaltic lava flows from both the central vent and from fissues, along with sometimes have a lava lake in the main caldera. These eruptions aren’t too much of a danger to the people who live near the volcano as it mostly issues lava flows rather than erupting explosively. It hasn’t erupted since 1967 according to the GVP, however, the volcano did erupt in 2005 (see above), displacing thousands of people.
NEW INFORMATION (2200 Pacific Time)
Just got this email about the eruption in northern Afar, Ethiopia. Sounds like it has released a significant amount of sulfur into the atmosphere:
Satellite instruments detected an eruption in northern Afar, Ethiopia
on November 3. The eruption first manifested itself as a large sulfur
dioxide (SO2) cloud drifting eastwards over the Arabian peninsula,
detected by the Ozone Monitoring Instrument (OMI) and the Atmospheric
Infrared Sounder (AIRS). MODIS data from the University of Hawaii’s
MODVOLC hot-spot monitoring tool (http://modis.higp.hawaii.edu)
confirmed an extensive hot-spot (presumably lava flows) near Alu
volcano, in the northern part of the Erta ‘Ale range. Details are
still sketchy and these observations are as yet unconfirmed from the
A total of 0.1-0.2 Tg of SO2 was measured in the eruption cloud by OMI
at ~1100 UT on November 4, by which time the SO2 cloud had reached
southern Iran. Using the OMI SO2 data and radiosonde soundings,
observed SO2 cloud drift yields a preliminary estimate of the eruption
onset time of 1400-1600 UT on November 3.
More details as they are available.
The headline for this entry sounds more dramatic than it is, but one of the last structures in the ill-fated Royal Gardens subdivision on the big island of Hawai’i finally met its fiery demise over the weekend. For those of you unfamiliar with the plight of the subdivision, Royal Gardens is part of Kalapana, and it was unfortunately situated quite close to the Pu’u O’o rift that has been erupting since 1983. Most of the subdivision has been overrun by lava flows since then, but one of the last two structures still being used was done in by the basaltic lava. The first link has a great map showing the October lava flows and where they have gone, along with some stills of the flows overtaking the house (in the video).