A Short Geologic History of Kauai, Hawaii

Hawaiian Islands from Space

Hawaiian Islands from Space


Kauai is the oldest of eight major Hawaiian Islands at some 5.1 MY. It sits some 170 km to the west of Oahu. There is a much smaller island called Niihau which sits some 28 km to its west. The rest of the string of Hawaiian Ridge islands and Emperor Seamounts stretch to the west and north from Kauai.

The island measures some 1,450 km2 and hosts a population of just over 67,000 per the 2010 census. As with the rest of the Hawaiian Islands, it sits under a belt of strong trade winds that bring abundant moisture along with the occasional hurricane. As such, it hosts lush rain forests, a major swamp and has for the most part a very wet, tropical climate, at least in the eastern and central upwind parts of the island. The northern coast is pounded with significant wave action out of the North Pacific, not unlike the north coast of Oahu. Wave action and precipitation are busily eroding the island back into the Pacific.

Precipitation Map of Kauai

Precipitation Map of Kauai

Kauai is one of the wetter places on Earth. Average precipitation in the lower elevations is in the 120 – 250 cm/year range. Places in the upper elevations have measured between 880 – 1,200 cm/year, all of which will move a lot of mud into the ocean over a short period of time.


The Hawaiian Islands proceed through four phases of volcanic activity. From Volcanism in Hawaii:

  • Preshield (alkalic)
  • Shield (tholiitic)
  • Postshield (alkalic)
  • Rejuvenated (alkalic)

Currently, the only Hawaiian volcano in the preshield stage is Loihi, off the southeast coast of Kilauea. This stage also emplaces some 95 – 98% of the total mass and volume of the island.   http://pubs.usgs.gov/pp/1987/1350/

As with the rest of the main islands of Hawaii, Kauai is composed primarily of a central shield volcano which built the island from layered basalt flows starting some 3.7 km below the surface of the waves. Like the other larger islands, Kauai has also had at least three and perhaps four major flank collapses, the largest ones being north and south which put up to half the original volume of the original island on the ocean floor, and a smaller one on its southeast side that did not put debris on the ocean floor.

Sea cliffs rise spectacularly up to four thousand feet

Sea cliffs rise spectacularly up to four thousand feet

Older papers and reports misidentify at least two of the partial flank collapses as lava-filed flank calderas.

The volume of the volcano above the surface of the ocean is thought to be over 4,100 km3 and its early rate of growth and evolution have been compared to that of Mauna Loa on the Big Island.

The highest point on the island, Kawaikini Peak is some 1,600 m above the waves. It is helps bound one of the largest calderas on the islands, measuring some 16 – 19 km across. There was more than one caldera collapse which was refilled by subsequent lave flows. The calderas were not formed by explosive eruptions. Rather they appear to be formed by subsidence much like what we see on the Big Island and certain Icelandic volcanoes. http://www.hawaii.edu/environment/ainakumuwai/html/ainakumuwaiislandformation.htm

A 1960 publication of the Hawaii Division of Hydrography entitled “Bulletin 13 – Geology and Ground-Water Resources of the Island of Kauai, Hawaii” gives an old school view of the basic geology of the growth of the island. Note that it was published a generation before the notion that massive landslides were part of the history of the Hawaiian Islands and misses those physical processes, describing the landslide effects as various versions of late volcanic activity. However it is a pretty decent description of the growth and construction of the island over time. http://pubs.usgs.gov/misc/stearns/Kauai.pdf

Seaside cliffs of Kauai

Seaside cliffs of Kauai

Initial Formation and Growth

There was a long and vigorous argument about how many major shield volcanoes formed Kauai. As it turns out, study of gravity anomalies under the islands published in a 2010 paper indicate that there were two major volcanic centers. The first was located between Niihau to the west and the second and younger center of activity is the center of Kauai itself. This means that Niihau, which is now privately owned and populated by some 250 Hawaiians, is the remnant of the first volcano. It appears to have suffered a significant flank collapse to the east some 5 MY ago as eruptive center of activity moved to the vent that would eventually build Kauai itself. http://www.soest.hawaii.edu/GG/FACULTY/ITO/Reprints/Flinders_etal_JGR10_Reprint.pdf

Kauai - Niihau Subsurface Map

Kauai – Niihau Subsurface Map

The remaining eastern portion of the initial edifice and the debris field of the collapse were inundated and covered by lava from the vent that became Kauai. The same erosive forces that removed the older island are now at work on Kauai itself. http://raisingislands.blogspot.com/2012/12/kauai-geology-nothings-where-you-think.html

Relief map of Kauai

Relief map of Kauai

The most massive part of Kauai is called the Napali formation. It is essentially constructed out of thinly layered olivine basalt lava flows sloping a few degrees down from the central vent. The formation is built from the ocean floor to the top of the caldera rim. The layers are thinly overlain with soil and occasional ash and tephra. As this was primarily a basaltic volcano, the source of the ash and what little pyroclastics exist were very likely the interaction between magma, wet soils and massive water load carried by the island. Ash and pyroclastics constitute less than 1% of the volume of material found in the Napali. This formation is completely permeable to water, which flows between the lava layers.

Total time to build the island was estimated based on the observed flow rate out of Mauna Loa between 1850 through 1940. Estimates range from 175,000 – 800,000 years, with the most recent estimates on the short side of that range for this and the other Hawaiian Islands.   The layering is easily seen along the cliffs that bound most of the island. http://www.hawaii.edu/environment/ainakumuwai/html/ainakumuwaiislandformation.htm

Okolele Formation

Toward the end of the shield building phase, there occurred a series of faulting, caldera and graben formation. Lava continued to flow and its formations changed from thin flows to massive, thick ones. This is referred to as the Olokele formation and exists primarily in the northwestern part of the island centered to the west of the caldera.

The Olokele is thought to have filled the caldera with lava which then overspilled and filled a few deeply cut valleys to the northwest. There were discontinuities toward the end of the valley and the lavas pooled, creating a rather flat area with a water-impervious floor. This area eventually became the Alakai swamp due to both its relative flatness and lack of drainage through the thick lava formation underlying it. Older studies suggest that the source of the lava is poorly known, though it appears to come from the same vent that built the entire island. Although not mentioned in any of the papers I was able to find, I would expect this time also saw the major flank collapses off the north and south coasts of Kauai as the island was no longer growing.

Alakai Swamp Trail looking west

Alakai Swamp Trail looking west

The formation of the Olokele also confused early geologists who initially believed the entire area filled with the thick lava formations was the caldera itself. The presence of breccias in the filled caldera between the Napali and Olokele was misinterpreted in early papers as evidence of significant explosive activity creating the caldera.

There is only a single flow associated with post-shield activity on Kauai.

Hawaiian Island Flank Collapse Map

Hawaiian Island Flank Collapse Map

Flank Collapse

The two major flank collapse landslides appeared to take place shortly after the island grew to its largest size some 5 MY ago. They removed half the above-water area of the island. These sorts of landslides are common in the Hawaiian Islands, as evidenced by some 70 flank avalanches littering the ocean floor along the eight largest islands. The Big Island already has over 12 described in various places. I would expect more in the future. http://walrus.wr.usgs.gov/reports/reprints/Moore_JGR94.pdf

Southern Flank Collapse Map

Southern Flank Collapse Map

The interesting part about the Kauai slides are that runout calculations indicate that the island itself must have sat some 900 m higher above the waves at the time of the flank collapses than it currently does. We have observed how the Hawaiian and Emperor chain subsides over time, with newer islands topping out at some two kilometers above the ocean and the very oldest some two kilometers below its surface.

Northern Flank Collapse Subsurface Map

Northern Flank Collapse Subsurface Map

Lihue Depression and Koloa Volcanics

About 3.5 MY ago, part of the original central shield volcano cone collapsed to the east. The slump to the east is referred to as the Lihue Depression.

Lihue Depression is under the eastern cloud layer.

Lihue Depression is under the eastern cloud layer.

At this point volcanic activity mostly halted for a 1.5 – 2 MY before resuming as the Koloa Volcanics some 1.5 MY ago. The Koloa are Rejuvenated alkalic eruptions which represent the final active phase of Kauai. Lavas and other eruptive materials from the Koloa also pooled in the Lihue Depression / Lihue Basin.  http://www.geo.arizona.edu/~reiners/Lihue.PDF

Late volcanic map of Oahu, Kauai and Niihue

Late volcanic map of Oahu, Kauai and Niihue

Much like previously seen in our three articles on Oahu, the Koloa Volcanics are characterized by basaltic lava flows, cinder cones, a small shield volcano, and numerous dikes. There is also ash and cinder (lapilli). Some 10 of perhaps 40 vents have been identified on the eastern part of the island. The activity concluded some 500,000 years ago. https://www.soest.hawaii.edu/GG/resources/theses/MS_2006_Gandy.pdf

Small shield volcano from Koloa volcanics

Small shield volcano from Koloa volcanics

During the entire life of the island, the entire edifice has been subsiding. Drilling as early as the late 1950s found sand dunes some 50 m under the water that could only have been formed above the waves. http://www.soest.hawaii.edu/wessel/courses/gg711/pdf/Detrick+Crough_1978_JGR.pdf

Columnar basalt dike

Columnar Basalt Dike

There are some interesting lavas associated with the Koloa. One is a columnar basalt found at Nawiliwili and Kipu in the Lihue Depression, where slowly cooling basalt in dikes opened by either rifting of the flank collapse or intrusion never hit the surface and was exposed to the surface by erosion. The columnar basalt is used in places much the same way as logs are, being used to construct roads and bridges.

Columnar Basalt

Columnar Basalt

Another is the Koloa Volcanics which have been described as having “interesting combinations, and commonly bring up pieces of mantle rock from very deep within them when they erupt.” The quote is attributed to a geologist named Peter Reiners. The problem appears to be a variation in what he refers to as trace elements in the melt incompatible with the temperature of the erupted magma. And this mixture appears to change during the course of a single eruptive sequence indicating some mix of cold and higher temperature mantle melts during the eruption.   http://www.geo.arizona.edu/~reiners/tempcomptrends.pdf

Present Day and Conclusions

As volcanic activity has ceased on Kauai, the action of waves, wind, rain and subsidence are in complete control. The island is a tropical paradise. But tropical paradises need to periodically renew themselves or they will end up kilometers below the surface as sea mounts over the course of a few tens of millions of years. Kauai will eventually meet that fate, but not in our lifetime.

Waimea Canyon

Waimea Canyon

 Additional Reading






1,174 thoughts on “A Short Geologic History of Kauai, Hawaii

  1. Good morning everyone!
    Very deep quake in Barda Big. That’s deeper located than the supposed second chamber, isn’t it? Maybe some mafma arriving from the depths, dunno… (yes, typo intended: mafic magma = mafma).
    Diana, we all welcome the Autumn! Since English language is 60% derived from Latin origin, it’s easy to understand why is it called so (Autunno, in Italian; Automne, French; Outono, Portuguese; Otoño, Spanish).
    We don’t have in tropical countries a definite season for when the leaves fall (some families, though, do loose their leaves regularly in periods of drought) and where they do, people simply call it “the season when the leaves fall” – couldn’t the Americans have just named it after that empirical observation?
    That’s my 2 cents of morning rumination.
    Another coffee, please!

  2. When plotted as a distance from the center, I used the GPS location as the center of slump, I believe you can see a definite pattern of downward angled lines to the quakes. It appears the downward slide is not straight down but angled downwards and to the north (right side of the plot).

    It also makes sense to see the large cluster of quakes at the bottom, it is under the most pressure and also the lack of M5 quakes in this region due to heat.

    • That’s quite an impressive bit of sleuthing… provided it holds up under scrutiny. The spatial relationship may have more than enough slop (noise) in it to render it invalid, but the concept seems quite sound. It would be ultra-cool if the locations from the fine grained quake data fits the idea in a future paper… showing the stacked diagonal faulting forming along the ring structure as as the floor slips away.

      You have either just given someone a thesis topic to work off of, or have beaten them to the punch.

      Do you have goodness of fit info for each of the suspected fault lines? That and focal mechanisms (beach balls) that agree with them would make this idea quite sound and able to withstand greater scrutiny.


        • If you have a list of those quakes, you might check with EMSC to see if the focal mechanisms match what you seem to have discovered. Look for strike planes that agree with the fault angles. (also look for ones that do not, the idea behind a theory is to see if you can disprove it)

          • Sorry, retired instructor here. 😀

            But, you seem to be closer to having supporting evidence for what you have found than I do with my wild arsed “volcanic Carbonyl Sulfate leaking to the stratosphere” idea. (leading to maintaining the persistence of the background Aerosol index.)

      • One thought, if this pattern is indeed correct and the ring faults are angled like this, there is no easy path to the surface.

    • Seriously good thinking! Now imagine the collapse as perpendicular to the planes of fracture as revealed by Ian’s plot.

      • Yes! if you look at it that way this whole process could have happened in the past.

        This would account for the very deep area on the north compared to the more shallow slopes all around the rest of the caldera.

    • One way to maybe check this out further would be to rotate everything, so your fault lines are transformed to something like flat horizontal, then plot the smoothed no of quakes/energy released down the right hand side and see if it has peaks where the fault lines are…

    • Hi Ian …….it all depends on which direction your view/looking from ….Is the “hard plate steel” plug??? falling to china?…… or is it simply hot magma, gases & liquids expanding, penetrating & rising?

      PS sorry to butcher your picy 😉

      • Yes, I can see this mechanism at work as well and it is very artistic 🙂 looks good.

        the only issue I have is that you would expect that area to rise and the last map of the distorted ice showed that area sinking, but that was quite a while ago

        • 1) Look very carefully at pic 2,3,4, the rim area was at that time rising at ~1m a day

          2)Read this very slowly again
          Dike emplacement at Bardarbunga, Iceland, induces unusual stress changes, caldera deformation, and earthquakes Agust Gudmundsson

          3) only the ice cap is depressing, there has been NO evidence that the caldera floor is collapsing

          4) DeepThought October 22, 2014 at 08:27
          Just noticed that on the VON & DYNC GPS that Bardarbunga appears to be moving into a Inflating trend over the last 14 days +20mm+- and movement direction has changed!!

          • Oh, I hear you loud and clear and am not dismissing this at all, it is a very valid mechism in my mind

            But, when I look at the areas with the most activity, it is subsiding and the area directly beside it to the east has only risen compared to level measured a few years ago so it may or may not be relevant. It does not change too much and the amount it has risen is small.

            The other reason for themrise could be a result the ice going over the rim itself and breaking

            • Look very carefully at pic 2,3,4, the NW-N rim area was at that time rising at ~1m a day ( pic 1 is a reference point only)

      • Maybe the arrows should point in the opposite directions. Magma is being drained from the reservoir and the magma pressure cannot quite carry the weight of the rock above. The main motion would be downward.

  3. That was an interesting earthquake this morning. At 15km way deeper than before, and very strong. Something gave way. It is also notable that it did not give an instant drop on the GPS, as it should have at this magnitude. That fits the earlier scheme that earthquakes more than 7km from the Barda centre (as defined by IMO) do not affect the GPS. But there was a slower drop 2 hours later which I won’t mention.

    • I wonder if the depth is correct since they said in todays update it was “on the northern rim” .

      From IMO

      During the last 24 hours around 70 earthquakes have been detected around the Bárðarbunga caldera rim, the strongest was magnitude 5.3 at 08:36 this morning on the northern rim. The event was preceded by a magnitude 4.7 in the same area just two minutes before.

    • If I believe correctly, it should be much more difficult to see quakes this large at this depth simply due to how ductile the rock is at that depth when compared to the shallow quakes.

      Definitely a very interesting quake, not sure what to make of it.

    • That deep, that large and that close to the “keel” of the upturned boat shape thought by some to be the deep(-est) magma reservoir of Bardarbunga. Yes, interesting indeed!

  4. We might be seeing an eruption in Colombia from Chiles (thanks down under for the heads up). Keep your eyes out – we may be seeing an eruption from a volcano that hasn’t erupted for at least 5000 years.

    • Hi Cbus! I don’t want to nitpick on you, but I am sure that my neighbors from ColOmbia would be glad if they see we have the correct spelling of their country. 😉

      • Ah, thanks! I know it’s a common mispelling and I definitely know better (my city is similar, but is spelled with ColUmbus instead of Colombus).

        • There is none (at least as of right now).

          Prior to 2013, this volcano was more or less thought to be extinct, so it wasn’t even listed in the Columbian Volcano Observatory website.

      • The level of activity of volcanoes changes to: ORANGE LEVEL nivel_2.png (II): ERUPTION LIKELY IN THE END OF DAYS OR WEEKS

        Tracking the activity of CHILES VOLCANOES AND BLACK HILL​​, GEOLOGICAL SERVICE COLOMBIAN OBSERVATORY Volcanological and Seismological GRASS (SGC-OVSP) highlights:

        Increased seismicity recorded since the September 29, 2014 to date, with about 40,000 earthquakes mainly related to fracturing of crustal material, and especially yesterday, October 19, is highlighted by presenting the largest number of earthquakes per day (4,700) since the installation of seismic monitoring network in Chilli and Black Mountain volcanoes in November 2013.

        Today October 20, 2014, at 2:33 pm (local time) an earthquake with higher energy level so far recorded, with a moment magnitude of 5.8, located in the vicinity of volcanoes Chiles – Black Mountain, at a depth less than 10 km (superficial), reported as felt to the cities of Pasto in the North (Colombian side) and in the South Quito (Ecuadorian side). This earthquake, around 30 events reported felt from 29 September to date are counted. The characteristics of this seismicity largely reflect cortical processes fracturing material; however, some of them show processes associated with magmatic fluid motion nature.

        During the assessment period, the network monitoring deformation of volcanoes Chiles – Black Mountain showing continuous changes associated with volcanic activity, detected only instrumentally.

        The behavior of this activity since 2013, particularly the recent increase in both number and seismic energy and recording signals associated with fluid dynamics, could show the instability of volcanic systems, which can evolve into an eruptive process in terms of days or weeks, which warrants a change in activity level from yellow to orange.

        Energetic event after today, there have been at least 15 earthquakes with magnitudes greater than 3.0, which have been reported felt by residents of the Reservation of Chiles. At the time of issue of this newsletter, keeps returning seismicity in the area of influence of volcanoes Chiles – Black Mountain, totaling about 1,200 events.

        Working together to analyze this activity and volcanic hazards associated with the Geophysical Institute of the National Polytechnic School in Quito (IG-EPN) continues. The SGC will continue to oversee the evolution of the phenomenon and report on the changes can be detected.

        (courtesy of Giggle)

  5. Remember those three mag 4s yesterday that all occurred within three minutes? Well check out this sequence from today. Four quakes in four minutes:

    21.10.2014 __ 8:36:35 __ 15.6 km__5.3 __ 99 __ 7.3 km NE of Bárðarbunga

    21.10.2014 __ 8:34:47 __ 6.7 km __ 4.7 __ 99 __ 5.0 km NE of Bárðarbunga

    21.10.2014 __ 8:33:16 __ 6.8 km __ 3.2 __ 99 __ 7.7 km NE of Bárðarbunga

    21.10.2014 __ 8:32:41 __ 9.1 km __ 3.0 __ 99 __ 6.2 km NE of Bárðarbunga

    • And note the extreme depth of these two that followed a few hours later … already manually checked by IMO.

      21.10.2014 13:51:30 65.141 -16.526 19.6 km 0.7 99.0 8.9 km NW of Herðubreiðartögl
      21.10.2014 13:51:17 65.152 -16.545 18.0 km 0.8 99.0 9.5 km WSW of Herðubreið

    • I’m wondering what could have set off a quake at 15.6 km depth… could part of the plug have melted to the point where it separated and fell into the vent leading to the lowest reservoir? Could the wall of the vent be cracking? Is it too far down for degassing to be a possibility? An M3.8 followed less than 20 minutes later at a depth of 10.3 km. These are deep rumblings for Bárðarbunga! 😮

      • There is a good possibility the M5 was far away from any chamber (the big red dot at the top of the chamber), the rest of that little sequence (4 in 4) is shown with green dots.

        It is so hard to see unless you look at it laid out on the map 🙂

        The other 2 deep quakes were on the opposite side (light blue dots)

        • Ian, you might want to check this… the green dot you’re using as a reference point for distance is actually the location of the GPS I think… I believe the other green dot is IMO’s reference point… I hope I’m wrong for your sake but please check it out. It could make a big difference to where these quakes are.

          • Yes, you are correct but all quakes on this plot are located by Latitude and Longitude not by distance, I just used that picture cause it was handy and easy to mark up 🙂

            • Thank goodness for that! I was quite worried about it! Okay, so the reservoir I’m talking about is the one located at 20-25 km depth, the one the mantle feeds into directly. That seems to be much bigger and wider than the one located at 10 km depth. I’m thinking that whatever set off that M5.3 is likely to be related to magma movement or internal pressure. It just doesn’t seem likely that it is outside of the main action. Could it be that the intermediate chamber is wider at the base than the top? I’m just brainstorming here for lack of actual knowledge 🙂

            • I see what you are thinking 🙂 and you may well be right but my lack of knowledge starts a couple of inches below ground as well

  6. An interesting lack of larger quakes, nothing over a 1 mag for almost 4 hours and when that came it was only a 1.2 , in fact there hasn’t been a quake over 2 mag since the 3.8 at 8:54. Gone a bit too quiet for comfort perhaps?
    Now watch a big one arrive. 😉

    • I’m thinking the same thing, Frances. It’s been six hours since the M3.8 followed the M5.3… given all the activity yesterday, that’s a long time for Big B to be quiet. I’m thinking maybe another M5-ish is in the works?

    • I think that has not been unusual after a very large quake. I am more surprised that the eastern/south-eastern side has seen so little activity. That was the location of most of the largest quakes before but is now down to one M4 per week. Pathetic. At least compared to expectations!

          • Does it! Oh now that’s interesting… that really helps to refine the picture I have in my head of Big B’s internal arrangements. 🙂 I wonder, Albert, is it feasible for there to be two central vents, one on the northern side and a smaller conduit on the southern side? If so, could they be running along side the plug and heating it on both sides? Would this help to lubricate the plug?

          • That should mean that once the influx of (new) magma ceases and if the surface vents are still open, the then unsupported S part comes crashing down rather quickly and spectacularly.

          • My two cents—if Bardarbunga has an eruption, it will happen at the fissure on the east side where there are already ice cauldrons left over from the initial dyke formation. No need to make a new path thru the edifice, a path to the surface already exists.

            • Overhill, the magmatic pathway is already fairly set at Holuhraun. There is a slight possibility that a new fissure will open up due to increased pressure, but right now, the process seems to be fairly stable.

              The reason why there is heavy speculation of an eruption at the caldera itself is due to a very different process from why there may be an eruption in the dikes.

              In the caldera, an eruption would likely form due to the breakup, under-pressure, and collapse of the caldera roof (or plug / lid). An eruption occurring due to a lack of pressure may seem counter-intuitive, but it’s a bit more complex than that with a huge lid of rock potentially collapsing into a partially molten magmatic region along with meltwater and other processes complicating factors further.

      • There’s just been an M3.2 located 3.1 km SSE of Bárðarbunga… it’s not even getting a mag 4 on that side at the moment… :\

  7. I am fascinated by IanF’s theory. I get horribly lost with the physics and formulae but thinking of the mechanics of a landslide and applying it to the inside of the curve of the caldera rim plus the downward pressure of the ice + “plug” would actually fit in with Ian’s proposal. (I think)
    Here is a paper that could throw some light on the possible reasons for the quake patterns .
    I do wish geoLoco could pop in and add some thoughts here. he is an expert. I amd most certainly not.

    Click to access Martel_2004_Marine_Geo.pdf

  8. To throw in another random observation: for the NE cluster (IMO data and terminology), almost all of the M3+ quakes deeper than 8.5km have occured in the last two weeks. This is not the case anywhere else along the rim. Before jumping to conclusions, there were two M5 quakes in Sept and early October just above this depth which may have calmed things down for a while!

      • ahh yes, now a torch/ headlight near the cameras. The lights I was wondering about seem way off in the distance. I guess people are taking advantage of ‘better’ weather. I am in awe of their hardiness.

  9. wow, it looks like those North winds are really battering Scotland and The Netherlands today. Hans better put his finger in the dike. (and wear a gas mask)

  10. remember way back when, when mila cam shook so bad in the wind? judging from the gas cloud from the eruption, the wind out there right now must be really something. this is Mila 2:

  11. Agimarc, nice choice of an article! Hot spots, but in a different tectonic setting. Will have to go through more thoroughly…
    But this still raises the question, about the tectonics and a hot spot. Here (Iceland) the tectonics rip apart, with the hot spot adding to the fuel but with its own thing, while in Hawaii it is rather the hot spot.
    Putting things together, early on they said that there are two cycles coinsiding here (Iceland), hot spot and tectonics.
    There was an article about hot spots in Iceland a while back; their interpretation was that the hot spot was really a large area upwelling from the mantel regime. Not a spindly noodle type of thing. And this thing is more or less under Bardar. Taken the thin crust in Iceland, it also seems that the other volcanoes are more or less connected to the same thing. Somebody quoted mantle convection something around 1m per year (!) of course correct me if you feel like it. Anyway it is quite slow. The interesting part is when the magma decides to just shoot out from the depths….
    And with an afterthought, we all live actually on top of the mantle, and most of the time, really, nothing drastic happens at all.

    • I am not an expert – but I think the mantle convection is like an upside down weatherforecast 1m/sec is a light wind and 1m/year might be an average mantleflow but I guess you get different speeds in different regions, and I’m thinking isobars of mantle pressure determine the speed and direction of mantleflow, probably coupled with the inherent viscosity in the substrate. If that’s so your mantle plumes could be inside out geohurricane/tornado. – low or high pressure ‘weather’ systems ???

    • Lapilius – also not an expert (and I didn’t stay at a Holiday Inn Express either).

      And I think you have it pretty close. The Icelandic hot spot happens to sit under the spreading ridge of the MAR. At the MAR, earth is building on the ends of the plates which sit on either side of it as it spreads. With Iceland, you have a twofer – not only is the crust weak at the MAR, but you have a pretty healthy hot spot under it that doesn’t have to work nearly as hard bringing new magma to the surface, as the cracks are already open and building new plate.

      In Hawaii, you have a hot spot essentially burning a series of holes thru the Pacific Plate as it travels across it, so you get a series of islands rather than a single big one. Though the plate does tend to flex a bit, it is not cracked open like MAR.

      Carl did a post on the Iceland hot spot around 30 months ago on VC. Worth your read. He suggests with pretty good justification that it is the same hot spot that powered the Siberian Traps some 250 MY ago.
      Cheers –


    • Hi Hen, Was just going to post that it looks like another double, not quite as big as the previous two doubles, but still continuing the pattern.

      • Actually a couple with a child. 😉
        21.10.2014 19:52:41 64.689 -17.490 10.1 km 3.5 99.0 5.7 km NNE of Bárðarbunga
        21.10.2014 19:51:50 64.685 -17.477 0.6 km 1.1 99.0 5.5 km NNE of Bárðarbunga
        21.10.2014 19:50:33 64.673 -17.464 2.6 km 4.3 99.0 4.7 km NE of Bárðarbunga

  12. Getting very frustrated to get this posted, mobile typing is not my strong point.
    This is the timelapse from the 19th to 20th of October with finally a long segment from cam2 as well. Music by Lisa Gerrard and Peter Bourke, ‘ Shadow Magnet ‘.
    I had hardly time to do anything with it ( sudden trip abroad for work ), but managed to make this. Otherwise it would have to wait until the weekend but then it would be a bit old news. I hope everything works well.

    Link fixed by Spica

  13. 34 3+ in 48 hrs, all at Barda. That’s back at the level of August 16 to Sept 7, when there was an average 30 per 48 hrs in the caldera, though then there were other 3+ at Kistufell and in the dike.

    Barda must have had more than 400 3+ quakes by now. The joint is jumpin’ !

    • Oh thanks, Laban! That takes my right back to my childhood – my father loved Fats Waller and had lots of his records. I loved dancing around to this one. Another favourite was called, I think ‘Your feets too big’ 🙂

  14. Am I making a mistake here or has the tremor on dyn dropped rather strangely today. If others agree do you have any idea why?
    This is the chart I am referring to and I am noting particularly the upper lines.

    • Hi Frances, I noticed that earlier this afternoon, it was around the time of the lull in quakes that you noticed. Bardar might just have been having a little nap. 🙂

  15. OT: I was in a car accident this morning while driving myself to work. Some guy in a green Ford truck cut me off and deliberately slammed on his brakes, forcing me to rear end him with my moms Jeep, causing some damage to the front. The other driver proceeded to get out of his truck and attempted to assault me through the window.

    • Hi Tyler, I really hope you are OK! It is very frightening when something like that happens! It is happening so much now in UK from people trying to get compensation for whiplash injuries.
      When I was in my twenties a madman in a lorry tried to run my brother and I off the road near Windsor, England. Just because we weren’t going as fast as he thought we should he was tailgating us on a dangerous twisting road. My brother touched his brakes to warn him to stay back and then he went ballistic and started to try to kill us, driving within inches of our bumper at very high speed! I don’t scare easily but that incident stays in my nightmares to this day. Thankfully we were close to a leisure park and could turn in at high speed or we might not have been here to talk about it. We walked back to the entrance of the road and the driver was waiting for us in his lorry further along the road. We decided an hour in the theme park was a small price to pay to escape a homicidal lunatic!

        • It is frightening I agree. Glad you weren’t hurt though Tyler. There are some crazy people out there. More and more people in many countries in Europe are using a dashboard camera now to prove what really happened in such cases. It may be worth investing in one. Take care if you can.

            • Glad you are ok. Here in the U. S. We call that “road rage” and sometimes ends with someone being shot. There seems to be a lot of angry people everywhere. They need to chill out and do some volcano watching!

            • Poor Tyler. It’s bad enough having a bump in the car but when people get aggressive that really shakes you. I had a bump a few years ago. A guy went into the back of me. I was hurt quite badly and I had some nice firemen getting me out of the back of the estate car on a board. I was in so much pain I couldn’t really appreciate those rather fine rescuers. 😀 Any ways what made it all nightmarish was the driver’s friends appeared and opened the door on both sides and were demanding my mobile phone and trying to grab my handbag (purse). Luckily someone had phoned for the police and ambulance and They arrived pretty quickly.. the men that were trying to get my belongings said they were going to phone for my family to come and help….Yeah! Right!
              So Tyler I do sympathise with you.

            • In many states, slamming on the brakes like that is illegal and can cause the one doing it to wind up being “Driver #1” on the accident report. Even if no citation is issued, insurance companies interpret “Driver #1” for being the cause of the damage. While going north out of Ft Walton Beach, I had a guy literally pull up beside me and try to muscle me off the road. We had contact, he dropped back and followed. Then he pulled off and I knew that he was going to summon FHP and report me as a “hit and run” so I pulled off and called them myself. No citation on my part… but he did show up as Driver #1 on the report. At worse I had some smudged paint from his car on my black truck. A little hard rubbing and a black sharpie (a brand of black permanent marker) later, you couldn’t tell anything had happened to my truck.

            • Glad you’re okay. A few years back, maybe 10 yrs ago, a lady had road rage in the Cincinnati, Ohio area. It ended with her causing the pregnant woman to off wreck killing the expected mother and unborn child. I believe she was 8 months pregnant, so she was charged with killing 2 people. Really very sad.

            • Sorry to hear that Tyler, road rage is a horrible thing. Frances’ ordeal sounds horrible too – like Stephen Spielberg’s first film “The Duel”. Well worth watching if you haven’t seen it, low budget but frightening.

    • I broke the window out of a friends F150 under similar circumstances. (I was 17). Some dudes that we were not on good terms with started a fight while we were in his truck in a parking lot. One reached in the driver’s window, grabbed him around the neck and started wailing on him with his free arm. I took a 16 oz glass Coca Cola bottle and bounced it off of his head, full swing. The bottle bounced and hit the rear window. He let go of my friend and thought about the fight for a few moments as he staggered around the parking lot, regaining his composure.

      We didn’t have any issues with them after that. The best part about it all was that neither one of us considered the fact that we had cutting implements available. That would have gotten us arrested.

      • Well my mom’s jeep is gonna need a new radiator and a new bumper. there was lots of cooliant leaking out of it after the collision.

        • Understood. Had my grandkid do the radiator in the pickup. Ordered the part in and he did the change-out (with supervision). It should be pretty straight forward. Lines, Cowling, Radiator. Additionally, a local parts house that deals in replacement parts won’t even deal with radiators. It’s quite easy to have one with a rotten core if you get a used one. Full on brass and copper ones will cost you through the eye tooth, but they can be repaired at a later date by a skilled tech should they develop a pin hole leak. Rather that do that, I just got an aftermarket new one for around 150 to 200 USD or so. It had provision for Automatic transmission fluid cooling lines, but I didn’t need them anyway.

          If you do the bumper yourself, BE FARKING CAREFUL. A damaged bumper can have a lot of stored energy if it’s been bent. When the bolts are released, it can spring out and strike you.

  16. now that the wind has calmed down a little the camera is shaking less and the focus of Bard2 is the best I can remember. you can actually make out some detail on the “peak” of the new volcano.

    • I like to watch this on my phone because I can really zoom in. Last night was so clear you could see big blobs of lava roll down the side of the wall on the left

  17. Billowing clouds of white and gold and red,
    A blazing trail of incandescent light,
    the torch of Baugur flaming at its head,
    Nature’s fiery beacon in the night.

    A new day begins. What shall it bring? Volcanic mysteries even deeper than the earthquakes at King Barda’s core while we, the watchers, in delighted thrall, puzzle over them. 🙂

    The GPS dropped a full half metre yesterday. Double and triple events within minutes of each other continue to stamp their patterns on the drumplots. Tremor plots falling. There’s a sense of change. An intricate interconnection of events coming to a climax. This is why we watch.

    • Barda is angry; restless ‘neath her icy bed.
      She stomps and roars and shakes her head.
      The winds they howl and turn to red.
      Her breath so foul, the birds are dead.

      She shoults and pounds, her anger bred
      from needing something to be fed.
      Times once were that the people’s dread
      brought her sheep, freshly bled.

      But now, to great folly, they bring instead
      equipment from the Iceland MET.
      Heed us not what ancients said?
      The god is angry, yet we make bets!

      Angry that we should have fled,
      insulted by our lack of dread
      confused to what direction she should head…
      I have no more words that end with “ed”.

    • The Bard is very inspiring. Not to mention another bard, Shakespeare who was not just a playwright but also a poet ‘bard’. 🙂

      • He certainly is – I’ve long been a huge fan of Shakespeare. And now I’m also a fan of the volcanic Bard – Bárðarbunga. 😀

  18. Dumb questions. What type of material is in radial dykes? Hardened rock or ductile material? Both? Very fluid magma? Depending on depth? Distance from chamber or mantle source?

    Does the magma from the mantle below Bárðarbunga comes up in macaroni-like dykes or one fat tube-like structure?

    • Not dumb questions at all and I look forward to seeing answers to them.

      I’d hazard a guess that the material in dykes depends on the composition of the source material, it’s age (in terms of how cool and hardened it is) and the stability of the dyke structure as well as depth. I do recall seeing some weeks back a comment by one of the experts to the effect that this current crop of magma might well be reactivating old magma in the dyke it’s using but that the addition would be very minimal and not significant in lava composition.

      I’ve seen diagrams that depict the central vent as macaroni-style dykes and others where it’s drawn as a single thick channel. I have no idea which is the case here but suspect it may be a combination of both. Hopefully someone who knows will enlighten us both. 🙂

      • Thanks Mopsy, I thought so too with the macaroni. Was just wondering about the placement of the dyke/dike after reading a paper on it. Who says there are not many older ones already crossing from the East to the North system (or others) and who says some of them with connection to deeper magma, either from other volcanoes or the mantle, are not also acting like little chambers where they are still deep enough. Just wondering about all kinds of things.

        • I always thought this intrusion was using existing dykes. It explained why it went where it did and so quickly. Magma is like water in that it takes the easiest route and will pound away to overcome any obstacles. This eruption is also making use of an existing crater field – in effect it is recycling what is already there.

          As for the magma, the experts at IMO, IES and the various universities are all certain the magma originates from Bárðarbunga because that’s what the instrumentation is telling them. The team from one of the universities (Cambridge I think), predicted the eruption on August 29 because they’d been tracking the magma flow underground with their instruments. They had 15 more monitors in store which they raced to put out around Holihraun just before the actual eruption took place. They finally finished installing this array at 10pm (theirs were the lights everyone could see on the webcams that night!). The fact that they were right is just one more piece of evidence saying the source of the magma is Bárðarbunga.

          • But apparently not only Bárðarbunga, as I read in that paper yesterday – by an Icelandic volcano expert, can’t find ref. now.
            Someone else speculated that the magma might in part also come from the system just south of the eruption site, but I have only seen that once and have no clue whether there is any proof in it. I do trust that paper I read though.

            • We can only keep our eyes open for what is reported in reputable places and take it from there. In the meantime, do what I do – revel in the joy of being completely inexpert – it gives us licence to say the craziest things! 😀

  19. Is there a specific name for a dyke with hardened material… 🙂 or simply Old Dyke or Fossil. Will old, hardened material in a dyke be reactivated or will a new dyke develop next to it?

  20. I wounder what the MRT activity pattern would look like if we encompassed all quakes over the past two months allowing a couple of hundreds miles either side of Iceland, this is two weeks below

    I have been watching this occasionally over several years.

  21. http://www.ruv.is/frett/mengun-rauk-yfir-6000-a-hofn

    Google translate –

    Considerable gosmengun the eruption of lava in the hole was measured Hofn now the fifth time in the morning. The concentration of sulfur dioxide in the atmosphere was about 6,000 micrograms per cubic meter at about hálffimm.

    No fixed station on the Port, there are people with hand instructions from Environment to measure the effect of sulfur dioxide. Contamination of 2,000 micrograms is considered unhealthy, according to data from the Environment Agency. It is likely that everyone has respiratory symptoms, and people are advised to close windows and raised in ovens and stay inside.

    • This shows very clearly that the vast bulk of the activity has been in the north east quadrant of Bárðarbunga. It’s astounding how much of a pounding that area has taken!

    • Thanks dfn for your animations, trying to pick out a consistent radial dykes or a ring fractures is all but impossible no matter how many times the BB data is churned by us all , …….as the whole BB northern area after 2700+ quakes is pounded & shattered into a zillion pieces (like a old car window screen).

      What is evident is that the VT & Hybrid quakes move in a upward trend towards the surface …………..unrecorded smaller quakes <M1 are running at 15-30+ odd per hour………large larger quakes are becoming more frequent & are concentrated in certain areas …… the caldera side of the northern area, the quakes undercut (called the reverse fault) to a total of 1.5km at about 8km deep, then BB appears to open up into a lager “chamber”.

    • along with all your previous graphs you put a lot of work into these, thankyou.

      There have been a number of variations in the eq’s away from the Northern area of the caldera, this weeks is showing the cylindrical shape that has varied from this to two fissures and back several times.

      Given the serious drop in ther gps readings since measurements began, I am increasingly ‘less’ inclined to think of the plug dropping and more toward it being displaced by magma pushing up around it. Instead of it finding a way out in conduits and fissures I suspect it is finding a way up.

  22. Magnitude mb 4.6 (Geofon, Potsdam, not yet reviewed)
    Region ICELAND
    Date time 2014-10-22 05:24:25.9 UTC
    Location 64.60 N ; 17.41 W
    Depth 5 km
    Distances 223 km E of Reykjavík, Iceland / pop: 113,906 / local time: 05:24:25.9 2014-10-22
    125 km S of Akureyri / pop: 16,563 / local time: 05:24:00.0 2014-10-22
    113 km W of Höfn, Iceland / pop: 1,695 / local time: 05:24:25.9 2014-10-22

  23. My oh my, look at the height of the fountaining and the width of the spillover… Irpsitadyngja is outdoing itself tonight! 🙂

    • I didn’t know it, hen, so thank you very much for passing it on. Even if I had seen it before, I would have no problem with your drawing my attention to it again. Over the past couple of months, I’ve read a great deal about volcanology and wouldn’t have a hope of remembering it all! I only know I haven’t read this one because it isn’t listed in my bookmarks which have become very extensive on this topic! 🙂

      As soon as I opened it I started reading it. I’ve now read it to the end though admittedly with a fair bit of background noise here so my concentration wasn’t the greatest. :\ Do please feel free to point me to the relevant paragraph. 🙂

    • Mornin’ Hen and all,
      That’s a nice link, it was already int the Bardarbunga info page, but no harm mentioning it again 🙂

  24. Just noticed that on the VON & DYNC GPS that Bardarbunga apears to be moving into a Inflating trend over the last 14 days +20mm+- and movment direction has changed!!

  25. IMO now giving the upgraded magnitudes for the early morning quakes.
    22.10.2014 05:24:24 64.670 -17.508 7.8 km 4.8 99.0 3.4 km NNE of Bárðarbunga
    22.10.2014 03:33:28 64.673 -17.478 3.8 km 4.2 99.0 4.3 km NNE of Bárðarbunga

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