Monday, December 19, 2016

Spectacular volcano videos: Identifying eruption processes

- Janine

It's the end of the year, it's cold (there is ice covering everything outside as I write this), and it's time to give your brain a bit of a break. That makes it a great time to watch videos of volcanoes. We are lucky that so many people post amazing videos of volcanic eruptions online for all of us to enjoy (see below warning), and we can learn a lot from them too. When I am looking at my satellite images of dome collapse block and ash flow and column collapse pyroclastic flow deposits on Shiveluch and Mount St. Helens volcanoes I have videos of these processes running through my mind. This is a short guide to what you are seeing in these incredible videos.

WARNING: There are very dangerous and life threatening hazards associated with retrieving this footage, and here at In the Company of Volcanoes we strongly discourage anyone from trying to take your own.

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This video shows the dome at Unzen volcano undergoing a partial collapse in 1991. This shows how a near-solid body of rock rapidly fragments down to smaller pieces of rock and ash, creating a billowing ash plume rising from the block and ash flow (a type of pyroclastic density current that originates from a dome collapse event). This eruption episode was a deadly one, killing 43 people, including 3 volcanologists - Maurice and Katia Krafft, and Harry Glicken, when a collapse larger than the previous activity caused a pyroclastic surge to sweep over where the group was standing. Having watched this video many times, I am still impressed by how rapidly this solid rock reduces to tiny pieces. I believe this footage of the dome collapse is not the one that caused the fatal pyroclastic surge, as the dome was covered in cloud during that eruption.

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This video, posted by Earth Uncut TV, shows another dome collapse, this one at Sinabung Volcano in Indonesia on 21 January, 2014. This eruption has been ongoing since August 2010 and numerous phases of dome growth/lava effusion and consequent collapse have formed a pyroclastic fan at the base of the volcano. You can see trees that have been killed by pyroclastic flows for scale. This high-quality footage shows the front of the flow racing down the volcano, and the expanding ash cloud above, entraining and heating air to expand and rise upward. You can see older deposits that formed lobes on the pyroclatsic fan ahead of the flow. Watch closely and you can even see a large 'dust devil' formed due to the hot ground.

The video below (by Photovolcanica) shows the Sinabung lava lobe collapsing, in slow motion, to produce a block and ash flow.



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Speaking of domes - a dome is a solid plug of rock that is extruded at the surface - there was an excellent chance to study how these work at Mount St. Helens volcano in 2004-2008. USGS took this time-lapse footage of a particular dome type - a spine, that you can see moving nearly vertically and crumbling as it goes. The highest recorded temperatures seen in cracks of a spine were over 700 degrees C, and growing at rates up to 25 meters per day. Read more about the Mount St. Helens spine growth and see thermal images here.
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Mount St. Helens put on a much bigger show on May 18, 1980. This video is made using the photographs taken by Gary Rosenquist, showing the first moments of the eruption. A cryptodome had been growing under the northern flank of the volcano, making the whole side of the volcano unstable. Immediately after a M5.1 earthquake the northern face failed and began to slide northwards as a debris avalanche, which depressurized the cryptodome, sending a lateral blast out from the volcano which you can see overtaking the debris avalanche.
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Block and ash flows are usually formed when hot dome rock collapses, so why not look at them using a thermal infrared camera. This above video was taken by the Montserrat Volcano Observatory of the Soufriere Hills volcano on Montserrat. You can see the hotter colors (yellow-white) of the base of the block and ash flow racing down the Ganges Fan, where the denser part of the flow is made of hot rock, and the cooler - but still hot, (pink-orange) expanding ash cloud forming overhead.

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On to a different style of eruption, and one from my home country - New Zealand. In 1995 and 1996 Ruapehu volcano erupted. Ruapehu volcano has a crater lake at the top, and when the magma hits this water we get a phreatomagmatic (magma + water) surtseyan eruption, where jets of water and ash shoot out of the crater and fall back down to the ground. In this video by Geoff Mackley you can see the white steam plume in the background, and the dark ash-rich jets rapidly rising, and pretty quickly falling back down because they are so dense.

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Another great video of a phreatomagmatic eruption is from Kuchinoerabujima volcano in Japan, taken by the Japan Meteorological Agency webcam that monitors the volcano. A 9 km ash plume rose from the Shindake crater with material quickly falling back to the ground and producing pyroclastic flows that you can see moving down the slopes.

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A very significant and deadly hazard at volcanoes are lahars -flows of water, rock, and debris that race down a volcano because of heavy rains, melting ice, or crater lakes. This particular video was taken by volcanologist Sandy Budi Wibowo on 28 February, 2014, and was shown at the recent Cities on Volcanoes 9 conference in Chile. He shows the different stages of a lahar on Merapi volcano in Indonesia. you can see the flow front going through, and the large boulders that are carried by the lahar.

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A closer view of just how much rock can be carried by a debris flow can be seen in this footage taken in 2003 at Semeru volcano in Indonesia. These flows are highly erosive and can carve out channels and destroy anything that get in their path. They can be triggered by even tiny volcanic events (like the Armero tragedy), or by non-volcanic related rainfall or the collapse of a crater lake wall. Video by Franck Lavigne at the University La Sorbonne. These can travel great distances away from the volcanoes and are a big hazard around volcanoes that house glaciers, like Rainier in the USA.

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Over to the name that (pretty much) no one outside Iceland can pronounce - Eyjafjallajökull in 2010, posted by Fredrik Holm. This is an incredible video of an ash plume right at the crater. My favorite part of this is the ballistics - the large chunks of rock that you can see being thrown out of the volcano in an arc projectile then hitting the ground nearby. This is something you definitely want to view from a distance.

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In this footage shot by a very lucky drone (spot the near-misses) you can see molten bombs and gas being ejected from Yasur volcano on Tanna Island, Vanuatu. This strombolian activity occurs when slugs of gas rise through a conduit, bursting at the surface and sending the walls of the molten lava bubble flying through the air. With the drone's very close calls you can see the molten bombs twisting and deforming as they fly through the air.

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For a much bigger eruption, and one that gave little warning, we go to Chile to see Calbuco volcano erupting on 22-23 April 2015. This beautiful high-resolution footage by Timestorm Films shows the 15 km high ash plume of the first of two large eruptions. This is a sub-Plinian eruption with a vertical ash column and a laterally spreading umbrella cloud at the top as the ash reaches neutral buoyancy with the surrounding atmosphere. More on the Calbuco eruption can be found in an earlier blog post here.

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This footage of an eruption at Sakurajima volcano in Japan shows the great show of volcanic lightning caused by ash or ice particles interacting within an ash plume, setting of these impressive electrical discharges. New research is being done looking at how tracking lightning strikes can help volcanologists understand large volcanic eruptions from space, so watch this area of research.

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Another great phenomena that isn't caught on camera as much are shock waves. This above video (by Linda McNamara) is of an eruption on Tavurvur volcano in Papua New Guinea. Just as the eruption starts you can spot a bright arc expanding away from the vent - this is the shock wave. You can see it going downwards across the cone kicking up ash, through the sky, and then hit the people on the boat. Shock waves occur when so much energy is released during an explosion that the wave initially travels faster than the speed of sound.

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What goes up has to come down, and volcanic ash fall is something that people who live around active volcanoes have to live with. Volcanic ash is not like the soft ash you find after burning wood, it is pulverized rock, glass, and minerals that are very erosive and bad for human health. The above footage is of the Ontake volcano eruption of September 27, 2014. The end of the video shows how quickly ash can block out the sun. You can learn more about volcanic ash, the hazards, health effects, what to do if you are caught in it, and see what it looks like under a microscope here.

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This footage shows clean up efforts after the Calbuco eruption. You can see how shoveling ash is like shoveling sand, or for those of you not around a beach (like me right now), heavy snow. This can easily collapse roofs, especially if water is added by rainfall, and is a large hazard around volcanoes that produce large ash columns. You can read more about the fate of volcanic ash here.

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One of the strangest lavas on Earth occurs at Ol Doinyo Lengai volcano in Tanzania. As you can see in the video above (shot by Jeffrey Brown), the lava runs kind of like water, and sort of sounds like it too! This is carbonatite lava - a cooler (500-600 degrees C) carbonate-rich lava that erupts as a black liquid, then cools to a white rock.

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A more run-of-the-mill (but still awesome!) lava is found on Hawaii - usually what people think of when I say I am a volcanologist (no I haven't been to Hawaii, yet). These lavas are much hotter and erupt at temperatures over 1000 degrees C. The CenterStudyVolcanoes posted this great high-speed footage of a lava flow in Hawaii, showing how the flow moves as breakout lobes, inflating as time passes. You can see the surface folding and breaking apart, giving the beautiful morphologies and textures you can see on many basaltic pahoehoe lavas.

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Not all lavas behave the same. A more viscous version is a'a lava, like this footage taken at Kilauea volcano on 1 June, 2010 by volcanochaser. Since there is a high glass content due to the rapid cooling (quenching) of the lava you can hear the loud 'clinkery' noise coming from chunks of lava breaking and cascading down the flow front. Lavas produce these a'a textures when the flow becomes more viscous due to lava composition, slope changes, cooling, or the increase in the number of crystals forming in the lava. You can also get 'blocky' lavas, where large chunks of lava ride along the flow surface.

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If you can't get enough of lava then a hot, churning lava lake is for you. This footage, shot by Geoff Mackley and his team shows the intense Marum volcano lava lake on Ambrym Island, Vanuatu. The hot, very fluid lava is gas-rich, causing the convection or bubbling at the surface of the lava body. Lava lakes are actually pretty rare so this is a chance to see how a large body of hot lava behaves. Note: I would never, ever encourage anyone to attempt to get this kind of footage.

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Another type of eruption where you can see hot masses of low-viscosity lava is during a fissure eruption, and for this we can go back to Iceland. In August of 2014 the Holuhraun eruption began north of the Bárðarbunga caldera and erupted enough lava over six months to cover an area of 84.5 km2. You can actually see how much of your home town/city would be covered by this amount of lava here. In this drone footage you can see how the eruption has built up it's own walls that hold the lava lake. You can also see the large amount of gas with high amounts of sulfur dioxide that became a hazard for people living downwind of the volcano. Video credit goes to DJI/Eric Cheng.

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Sometimes underwater eruptions go completely unnoticed, and sometimes the only clues are huge pumice rafts that cover thousands of kilometers and travel with ocean currents for months.This video posted by Stuff.co.nz was taken by a pilot, and shows the pumice raft that originated north of New Zealand round the Tonga-Kermadec trench. If this wasn't seen by a pilot, we might not even know it happened.
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Aside from being incredible videos to watch, there is so much we can learn from watching footage of volcanic activity. We can calculate eruption rates, timing and sequence of events, volumes, temperatures (with thermal infrared), velocities, and where hazardous rocks tend to fly during an eruption. All of this helps us to understand volcanic processes and hazards, so we can eventually get people out of the way and protect lives.

This, and it provides inspiration at the end of a long day of Ph.D. dissertation writing.




Note: Where credit isn't given to the source, the original source was not listed. Please give full credit to any videos and images you post online.

Tuesday, December 13, 2016

Interpreting historic eruptions with old dusty hidden treasures: Introduction to historical and social volcanology

Guest Blogger Jazmin Scarlett

Follow her on Twitter: @scarlett_jazmin
Jazmin shares more of her adventures on her own blog: Phdvolcanology.wordpress.com


My name is Jazmin Scarlett, I am a PhD student in volcanology and I am not trained in geology, geophysics or geochemistry.

I am trained in understanding hazardous processes and how humans interact with them. I am, therefore, a weird mix of physical and social scientist. I understand the processes behind volcanic activity, but I mainly understand the many characteristics of volcanic hazardous phenomena. I understand how they impact on the natural and built environment and in turn, I understand how humans respond, mitigate and prepare against them. However, the interactions between hazard and person is more often than not more complicated than just hazard + human = impact.

As well as understanding the volcano and its hazards, what is around the volcano is just as important. Infrastructure, settlements, topography, climate and so on. Humans are far more complex, so responses, mitigation and preparedness goes beyond what is visible (e.g. running away, building a wall, evacuation drills), it involves understanding what makes us tick when it comes to confronting hazards and risk. This has led me to learning about theories and concepts with sociology, psychology and anthropology.


The village of Byera, located in the high risk volcanic hazard zone.


My approach to ‘social’ volcanology has been a mixture of volcanology, socio-psychology and disaster management. This all started with my masters dissertation into volcanic risk perceptions on the island of St Vincent in the East Caribbean. In order for people to do questionnaires and a semi-structured interview, I first had to learn about the volcano in question, La Soufrière and, its volcanic hazardous phenomena. After that, I had to understand the society, its common problems and other hazardous events (hurricanes, agricultural pests, crime and so on), culture and the country’s take on disaster management and relation to its volcano. After that, it was the matter of being a non-biased and open researcher to get the most representative results as possible.


A street leading to the village of Bellevue in the medium risk volcanic hazard zone.


I learnt so much from the project: about myself, about the island my family is from, about the volcano and importantly, about social volcanology. The sub-discipline itself is quite young, so at the time I felt I got an equal amount of questions and answers! I learnt that the ‘social’ aspect of volcanology involves the need for the researcher to really strip back and understand the society and its connection to its volcano(es) and to be patient with participants. I spoke only to the lay-public, so despite keeping everything as jargon free as possible, there were still things I had to take the time to explain. I was going into the project using human geography techniques…but came out learning about socio-psychology and a bit of anthropology!


The beginning of the Windward volcano trail.

I took all the questions and answers from that project into my current PhD which is still looking at St Vincent. The initial innocent question was: “how did people respond in the past?” and it has now got me using historical geography understanding. My current project is investigating three historical eruptions of La Soufrière impacts on the society, alongside how the society developed with the volcano. This has involved all aspects of social volcanology (perceptions, development, awareness and so on) within the historical context. I have to understand factors such as the economy, colonial relations with the British Empire, the societal hierarchy, the slave plantation system, emancipation and the significance of gaining independence. It is split up into three parts: reconstruction of the eruptions using archive sources (across six different archives in three different countries), impacts on the agriculture sector (sugar, cotton, arrowroot, banana and others) as well as certain parameters of the society (responses, recovery, disaster relief, resilience) that may have influenced the ‘co-volcanic society’ today. ‘Co-volcanic society’ is a new term being created between myself and my supervisors about the reciprocal relationships between volcano and society.



A pile of archive documents related to the 1902 eruption of La Soufrière. These documents belong to The National Document and Archive Service of St Vincent and the Grenadines.

A Barbadian newspaper article with a strong religious reaction to ash fall from the 1902 eruption. Barbados always experiences ashfall from St Vincent due to the dominant Easterly winds.

Part of my historical hazard mapping experience. These are datapoints with descriptive observations of pyroclastic density currents for the 1812 eruption, often referred to as “lava” during this time. They are mapped onto a 1796 map.


On the main Leeward road in the southeast of St Vincent.

School children learning about volcanoes during volcano awareness week 2016 on St Vincent.

Governmental correspondence for Barbados during 1902. Book is within The National Archives in London, UK.

One of my interviewees in the town of Chateaubelair. He shared his experiences of the last eruption in 1979. He moved his family to a safer location south of the island then returned to volunteer helping sick people evacuate.

Being a historical and social volcanologist requires me understanding the volcano and the exposed population within the historical context. It is a unique approach to volcanology and one I am proud to follow. There are many ways to understanding volcanoes, mine is just one of them.

Photograph taken by volcanologist Dr Tempest Anderson at the Orange Hill Estate house after a pyroclastic density current on the 7th May 1902. Photographs held at the Yorkshire Museum, UK.

Diary entries from American barrister Hugh Keane, who observed the 1812 eruption. Diary held at the Virginia Historical Society, Richmond, VA


La Soufrière crater in April 2016.



Monday, December 5, 2016

The trees of Calbuco

-Alison
Most of my research can be described as looking at rocks to figure out what happened in the past.  There are many deposits from volcanic eruptions that don't just contain rocks. As volcanic soils are very fertile, many volcanoes are forested which means that falling ash or debris flows interact with trees and other plants. The way trees are damaged by the eruption can tell us a lot about what happened. The trees in the blast zone of Mount St. Helens are a dramatic example.
Trees blown down by the 1980 later blast at Mt St Helens (image from 2015).
I was recently lucky enough to visit Calbuco Volcano in the lake region of Chile. You may remember the impressive pictures of Calbuco erupting at sunset on April 22, 2015.  This heavily forested stratovolcano produced a large plume (which dropped tephra, coarse scoria on the slopes of the volcano and ash all over eastern Chile and Argentina), pyroclastic flows, and lahars (debris flows) from melting glaciers and later rain. Janine did a post right after the eruption that contains lots of amazing videos and photographs of the impacts of the ash on people who live near the volcano.

The deposits from this eruption provide ample chances to see how falling and flowing rock interacted with trees. The different types of damaged to the trees helps us figure out more about what happened on the volcano and in what order. The falling scoria buried trees and fences on the slopes of the volcano. This knocked branches and leaves off of many trees and killed many pine trees, but many trees continued to grow! We know the scoria fell mostly straight down, or there would have been more damage to these threes.
These trees were twice as tall before being covered by 60 cm (or roughly 2 feet) of tephra (scoria, cooled gassy magma). The tree is still growing a year and half later.

Pyroclastic density currents are both fast and hot. These currents form when the column of hot rock and gas collapses and instead of gently raining rocks down like the tephra, they form currents of debris that travel down the volcanic slopes. They snap trees in half and burn healthy wood to charcoal as they pass. To scorch wood the flows are typically expected to be 300 C (572 F) or more. For older volcanic deposits this charcoal is very useful to date the eruption, as well as confirm it was hot.
Burnt wood carried by a pyroclastic flow is now part of the deposit. This log is 60 cm or almost 2 feet long.This tree was knocked over and broken by the flow, so we know the flow was hot and fairly dense.

This tree was burnt and broken, but still standing after the 2015 Calbuco eruption.This means the tree was damaged by hot pyroclastic density currents, but they may not have been dense enough or carrying large enough clasts to knock the tree completely over.

This tree was buried by hot pyroclastic debris, but it didn't fall over until after the base had been completely burnt. This helps us reconstruct the timing of the eruption and how powerful the flows were.
These trees were killed by the pyroclastic flow that burnt the lower part of the trunks and singed the tops, but were later exposed when rainfall eroded the debris without knocking them over.

We also saw trees that had been damaged by passing lahars (debris flows). These are slurries of debris and water formed when the hot pyroclastic flows melted glaciers and mixed with water. These flows may be hot near the source, but cool down as they travel and incorporate more water. Lahars also formed after the eruption ended with heavy rains mixed with all the loose debris of the pyroclastic flows. These mixtures can look like fast moving cement and carry a mixture of sand up to big boulders. These flows knock things down, erode deep channels, and abrade things in their path.

The upstream part of this tree had its bark removed up 2 m above the top of the deposit (more than 6 ft). This also helps us know what direction the main flow was headed.
This large boulder became lodged against this tree trunk at the side of the river valley. You can also see how high the bark was scraped off the tree.
Looking closely at these trees you can spot smaller pebbles embedded in the wood.

This log is part of a root that had grown into previous rocky deposits and been ripped up by a lahar in 2015. The ruler is 20 cm long, or about 8 inches. Logs like this really show how powerful the lahars are to rip up trees with such large roots!

The abrasion of a passing flow can sand a tree down from a circular trunk to one like this. The bark and shape are preserved on the underside of this log, while the top half is almost gone!

The logs then become part of the deposit and stick out of the ground at all sorts of weird angles.

The water from the lahars and later rain storms move the loosest rocks and trees leaving propped logs balancing in their wake.

These trees are a good example as to why geology can be compared to forensics. We can look at lots of different types of evidence after an event to reconstruct what happened and when. Documenting fresh deposits like these also help us do a better job of reconstructing older events so we have a better idea of what volcanoes can and have done in the past, so that we know how to better prepare for future eruptions.

Friday, September 9, 2016

Rocks can be movie stars too


-Alison

I still remember my first geology class as a freshman in college. I was so certain geology was for me that I was ready to declare my major before I even got to campus (very few geology majors start this way). It didn’t matter that I’d never had an Earth Science class or knew the first thing about rocks, but I knew geology was the gateway to movie-worthy jobs like Paleontology and Volcanology. The first time I was given a tray of rocks and they asked me to figure out how they were different. I didn’t have a clue beyond ‘sparkly vs. not sparkly.’  But telling rocks apart isn’t some innate skill, it is the result of observation. Anyone can do it, if you take the time to look at a rock for its parts, not just the whole. With the right push from my lab instructor it didn’t take long to start seeing all the differences that I now take for granted when looking at rocks. The size and shape of crystals, the weight, the way they break etc. I then learned how to look at the rock with more than just my bare eyes, how to slice up the rock and look at the millimeter and micron size differences, and even to use x-rays and look at the atomic differences. Now the big difference between rocks are so obvious that my husband and I will try to identify rock types from the car while driving down the highway (and do a decent, though imprecise job of it). A lot changes when you know what to look for and how to look.
What is so special about this rock? It has sparkly bits and not sparkly bits! This is a piece of the Fish Canyon Tuff (one of the largest explosive volcanic deposits in the world!) and is made of biotite crystals, pieces of other rock, pieces of pumice, and wee bit of  lichen. Knowing all that helps us figure out how it formed. Step 1: what is rock made out of, Step 2: what does it take to pulverize other rocks then stick them back together in this combination (hint: volcanic explosion). 
A lot of geology is the interpretation of old rocks and landforms, to figure out what happened in the past. We look for evidence of slow things like erosion by wind or tectonic deformation (100’s to 100000000’s of years). We look for things that happen quickly like meteorite impacts and volcanic eruptions (seconds to years). With enough observations we can look at a landform and be able to tell if it was formed by a fast or slow process. But not all rocks or landforms are always that cooperative. Since geologic processes don’t just stop after something cool happens, most landforms, even the fairly young ones, have changed since they formed. Take for example, Mt St Helens. After 30 plus years the deposits have been altered by wind, rain and plants. It is a fascinating laboratory where we can watch our planet change. But if you want to look at a 400 million year old rock, sometimes that change makes the job of interpreting it harder.

Also, while the processes that shape the Earth are numerous, and the rocks that change are many, sometimes very different processes can form very similar looking landforms. I already wrote a post about holes in the ground. There is a great word for this called 'equifinality' that I just learned the other day from a neat blog post about gullies and channels on Earth and Mars by @PanetGeomorpho. Here, on In the Company of Volcanoes, we compared holes formed by the relatively slow collapse of limestone caves to impact craters made meteorites, and maar craters. At first glance, and even second and third, these landforms have a lot in common. To make matters worse, when we compare landforms we also need to keep in mind that what we are studying likely did not form yesterday so we didn’t see the process, and the landscape has changed since that landform was created. Comparing fresh impact craters to old impact craters is hard enough on its own, but if we want to compare fresh sink holes to ancient volcanic craters where do we begin? The short answer is one observation at a time.
Large sinkhole formed in 1972 in Central Alabama. 425 ft long, 350 ft wide, and 150 ft deep. Courtesy of USGS.
On my recent trip to Morocco I was very excited that we were going to see a landform that may be familiar to many readers because it has appeared in movies like the Mummy, Hidalgo and Spectre.  Gara Medouar is one of the names for this  raised circular ridge. It has been used to represent whatever Hollywood needed at the time, from an impact crater to an ancient Egyptian city. But what is it really? Geologists, and our patient friends and family, enjoy the challenge of trying to identify filming locations and landscapes in movies (See this awesome blog post by @trueanomalies trying to do just that). What is extra exciting is taking that hypothesis and going to the site in question and hanging out with local experts to find out if you were right.
Gara Medouar as it appears in Spectre (MGM 2015).
This ring-like ridge has some features that are similar to an old eroded impact crater and to a tephra ring from a phreatomagmatic volcano. My quick look at images before I left said that a tuff ring, a small volcano made by explosions between magma and water, seemed pretty reasonable. Since I have a fondness for volcanoes, that became my favored interpretation that I was hoping to test on my field trip. You can see the similarity to Fort Rock in Oregon that is an eroded tuff ring (below).  Even though I knew that part of Morocco isn’t particularly volcanically active, and it is not impossible, but rare, to have one of these volcanoes all by itself, I was still excited to get to see it in person and find out for myself.
Fort Rock in Oregon is an eroded Tuff Cone, or a mostly phreatomagmatic volcano. It has been severely eroded so only part of the structure is left. Gary Halvorson, Oregon State Archives, via Wikimedia Commons
For anyone who cannot get to Morocco we can look at Google Earth. Using these images we can see the shape of the structure and check out its neighbors and see there are other similar features nearby. The Gara Medouar itself shows some layering that has been eroded. The layers appear to mostly be dipping in toward the inside of the structure.


Gara Medouar in Morocco from space. Note the layers of rock visible and they mostly point toward the center of the structure. You can also see all the roads made by the movie industry for filming. Image from Google Earth.
The first thing we can see when we zoom away from the famous landform is the roads and infrastructure built up by the movie industry. We also can see lots of other larger ridges and mountains. To the south of the landform we see a much longer ridge that has more of an elliptical shape and is much larger than Gara Medouar, but still shows layers dipping inward. There aren’t many similar circular structures nearby. If there had been that might have supported the volcanic hypothesis. While it being alone would be in line with a meteorite impact structure, the inward dipping layers suggests another model of formation is needed. This consistency across multiple large structures suggests there is something about the rock they are formed from. To learn more about this, we need to get closer again.


Zoomed out image of the area around Gara Medouar. In the lower central part of the image we can see a larger structure also formed by inward dipping ridges, but it is much larger and more elongate.
Our group traveled from Marrakech through the Atlas Mountains to the desert. Along the way we stopped to look at many fascinating outcrops of rock to learn about fossil life and the tectonic forces that formed the Atlas Mountains (Africa smashed into North America).  As we got closer to Gara Medouar we stopped to look at the rocks that formed the nearby mountains. They are all Devonian (350-400 million years old) limestone full of fossils of awesome marine creatures that lived in an ocean between Euramerica (what would later become North American and Europe) with Gondwana (northern Africa now). Around 300 million years ago these two continents smashed together to form the Atlas Mountains and on the other side of the ocean formed the Appalachians. The collision of continents is a slow messy process that deforms rocks for 100’s of kilometers in either direction away from the collision zone. The rocks we are talking about in Morocco were crumpled by this process creating folds and faults. Later, about 60 million years ago, the Atlantic Ocean formed from a rift between these two continents, separating the mountain ranges.

The evidence of this collision was visible in all the outcrops we visited on my trip. Rocks that would have formed in nice gentle flat ocean basins were now tipped on end, bent and wrinkled and generally messed up.
Excellent example of a tight fold in the Anti-Atlas mountains on our way to see the Sahara desert. The cliff is about 8 m high.
On the way to Gara Medouar the rocks had a gentle undulating sort of deformation. Where the folding took place over kilometers making local highs and lows that were later eroded to make long curved ridges with layers of rock exposed in the crests and sides of these ridges. We frequently look at folds in 2 dimensions (image above) but this all happens in 3 dimensions, so the rock in this area would have resembled an egg carton. These round folds were then exposed by millions of years of erosion. Because of their shape what is left at any given time only shows part of the shape. So our movie star Gara Medour is truly an excellent actor, playing any role that movies require of it, but it remains a humble eroded fold.
Folded Devonian rocks that were not yet covered by a sandstorm about 2 kilometers from Gara Medouar. The deformation that these rocks show is similar to the small ring-like structure that is famous in movies.
Unfortunately for my group, when we got to the site we were beset by a mild, but impressive to the out of towners, wind storm. So when I looked to Gara Medouar I saw merely a shadow of a ridge and lots of flying sand. The sand did not deter us from looking at the excellent fossils of cephalopods from the 400 plus million year old ocean, nor a seasoned local from selling some of his pristine fossil finds. It did, however, prevent me from taking my triumphant photo of the landform's tectono-sedimentary past up close. Our hosts had seen studied it numerous time, and could show us ample evidence in the landscape and photographs to support their interpretation, and while I was disappointed to not touch it, I left satisfied being reminded that there are always more options than we initially expect. For more information on Moroccan Geology check out the Ibn Battuta Centre. As our group was full of planetary geologists interested in eolian processes the stop was considered a success, if not for the original reasons. That is one of the many reasons I enjoy being a geologist, most adventures turn out different than expected, but there is always something to be learned.
Consolation prize, Devonian fossils and a wind storm!



Tuesday, July 19, 2016

In memory of Om Leo (@LeopoldAdam)

- Janine and Jeannie Curtis

Tree planting Gunung (Mount) Merapi's west flank

Many of us online know of and had interacted with Leopold Kennedy Adam - @LeopoldAdam on twitter, and the administrator of volcano communication websites such as Gunung Slamet. We know him through his excellent communication of the activity and hazards of Indonesian volcanoes, in particular, Sinabung. This ongoing disaster has been largely forgotten by international media and it is through efforts of those in Indonesia, like Leo, that have helped keep the world aware of the volcanic and human impact of these events.

In August of 2010 Sinabung volcano (Gunung (Mount) Sinabun(g)) entered a phase of unrest. Since then the volcanology community has been watching. Many of us have been watching from a distance like myself, through social media, videos of incredible and dangerous pyroclastic flows, and using Google Translate to read official and media reports of the sometimes deadly eruptions. It is a heartbreaking situation where local villages have been evacuated, leaving all that they know, and attempts to tend to their homes have resulted in fatalities.

Major volcanoes of Indonesia (courtesy of USGS, adaption of CIA map 1997 from Simkin & Siebert, 1994).

This continues to be a very serious situation, and is not an isolated event in Indonesia, you can see in these maps the sheer number of volcanoes, with 460,000 people living within 10 km of an active volcanoes in North Sulawesi alone (USGS).

Population and volcano density in Indonesia (courtesy of USGS).
It is important when sharing information on these events to use trusted sources, there are far too many inaccurate and blatantly fear-mongering news articles reporting "facts", when they are only interested in gaining page views. In fact, this is one of the reasons I started using twitter in the first place - to find and provide facts on volcano activity and information on volcano hazards.

One of the sources I trusted and greatly appreciated was Leo. Along with his network of friends he posted up to date images of the activity of Sinabung volcano and information on the state of activity. One of the most obvious reasons for using social media is to connect. We have a relatively new way of connecting with people around the world who have interests similar to our own, and there is a strong group of passionate volcanologists on twitter - see the list @kenhrubin put together here.

Something I took for granted was how checking the online activity of volcanoes most days on twitter would form friendships, and how my appreciation for these people would grow. When Jeannie told me of the passing of Leo I was heartbroken, it felt like I lost a friend and I am sure that many others feel the same way for someone we did not get a chance to meet face-to-face. The following words are from Jeannie, a friend of Leo who worked with him on social media pages to educate the world on how the volcanoes of Indonesia affect the many people living there.

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Leopold (Leo) Kennedy Adam, known to many as 'Ulik', and 'Om Leo', (meaning Uncle Leo a term of endearment and respect by thousands), was born 22 March 1962 at Poso, Central Sulawesi and moved to Jakarta as a young child. He married, had two children and studied Geology at Bandung Institute of Technology in the 1980s, living in Bekasi, Jakarta, West Java. Later, Leo was employed with the Secretariat of School SMA Negeri 1 aka Boedoet 7, a religious Higher Secondary School in Jakarta and as part of the job, he took up residence in East Jakarta's Velodrome at the Boedoet 81 Sekretariat Office.


Leo, a humble, family man, was spiritual and devout, loved athletics, volcano backpacking, lots of coffee and had a huge passion for volunteering in disaster mitigation projects, religious and athletic events. He spent many years volunteering his time as a Geological Hazard Mitigation National Disaster Volunteer in times of volcanic disaster; recruiting volunteers, Disaster Mitigation training drills and in many conservation efforts such as the mass tree replanting on the west flank of Gunung Merapi.

Leo's biggest passion was athletics, he mentored and supported so many athletes and track/field events at the Sports Arena (GOR) Velodrome, Pulogadung, East Jakarta, where he lived, onsite. Leo had a legendary knack of acquiring event results even before the media, and forwarded these results nonstop to the very grateful athletes and coaches. Many athletes mentored by Leo, speak of his unconditional faith in their ability; as a motivational speaker; and hands-on support and inspiration in their endeavours to become athletes.

Leo with athletes at the Velodrome.
Leo was very well known in Social Media on Facebook and Twitter for his unrelenting updates on Indonesian volcanoes and disaster mitigation. Leo started the Facebook page 'Gunung Slamet' with Boemi Djawa (https://www.facebook.com/gunungapi.Slamet/ …) and was an admin on many other Indonesian pages and groups. His name is synonymous with Gunung (Mount) Sinabun(g) updates and using the photos taken by his friends, Boemi Djawa, Endro Lewa, Tibta Pangin and Sadrah Peranginangin, he has supplied the world for years with non-stop updates about the volcanic state of Gunung (Mount) Sinabun(g), Gunung (Mount) Slamet, other Indonesian volcanoes in the news and Disaster Mitigation volunteer programs and assistance.

Leo was quick to admonish others, if he felt they had disobeyed the Disaster Mitigation rules. He once wrote "We are here in Indonesia trying to educate and to rise up the capacity of our people on handling the disaster mitigation". When a stuntman snowboarded into the very active Gunung Bromo in February 2016, Leo was extremely offended and wrote, "It is not about what things you believe in Life... It is about the regulation people here must obey, because it is about their lives" and "For every single disastrous volcanic activity, the official institution try to make it Zero Victim".


Leo, a long-term smoker, had battled known lung problems for many years. On 13 July 2016, at 8:30am, Leo was found deceased in his employee residence, at the Sports Arena (GOR) Velodrome, Pulogadung, East Jakarta, aged just 54 years old. Leo's death has left a great hole in the reporting of Indonesian volcanic news, made even harder, because he has personally touched our hearts and shared his personality with us.
Selamat Jalan Om Leo! Goodbye Uncle Leo!

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Jeannie Curtis @VolcanoJeannie Twitter/Facebook















Wednesday, June 15, 2016

A whirlwind sampling of Morocco (emphasis on wind)


-Alison

Thanks to an invitation to talk about rocks, something I am sure you can tell I enjoy, I got the opportunity to travel to Marrakech, Morocco in June. Talking about my research is an important and enjoyable part of my job. It is a means of sharing the latest results, reaching out to groups who study different but related fields, letting the public know what geologists like myself do, and to teach classes to the next generation of geologists.
Mosaics in Marrakech, Morocco.

This trip to Marrakech was for a conference of sedimentologists, where this year’s theme was to bring terrestrial and planetary scientists together to talk shop. Sedimentology is the study of rocks and the sediments that are made up of parts of other rocks, chemically precipitated rocks, and rocks that involve the help of animals to form at the Earth’s surface. Sedimentology is also the study of the processes that form, transport, and deposit the particles and chemicals that become part of sediments and sedimentary rocks. Sediments and sedimentary rocks cover the majority of Earth’s surface and are where most fossils are formed, preserved, and found. A lot of processes that are involved in making sedimentary rocks are slow and tedious, like the evaporation of a lake bed to form salts. Others involve the slow settling of small particles on the seafloor. The reason I was invited to this conference was that this meeting, the 32nd meeting of the International Association of Sedimentologists, had a special session on extreme sedimentation, things that are bigger and faster than the sediments most people think about.
Also I went to Morocco to eat all the couscous I could fit in my face.
These extreme sediments form rapidly after the impact of a meteorite, when a mountain collapses, when a tsunami rushes onshore, and, you guessed it, when a volcano erupts explosively! Anything that is made up of discrete pieces of other rock get called clastic (from the Greek for "broken"), and then we can add modifiers to our hearts content. Deposits made by explosive volcanic eruptions are made up of broken bits of rock, and we call them things like pyroclastic (with  a Greek prefix meaning "fire") when those particles are hot, or volcaniclastic when they are more generically made up of things that needed a volcano to exist (bits of old lava and ash that were cold before becoming part of the new sediment).  I study volcaniclastic rocks, mixtures of rocks made from fresh rocks cooled from magma, old volcanic rocks that got disrupted by more recent activity, and other rocks that were just in the way. The way I describe these deposits is very similar to the way that a sedimentologist would describe rocks formed by any other process that transports its ingredients at Earth's surface. The big difference is that most sedimentology works with rocks that are emplaced in mostly horizontal beds, while volcanic rocks can fill in valleys or be on steep slopes, as well as nice horizontal layers. We also tend to use slightly different terms, but the principles are so similar the name changes frequently seem silly (e.g. sand sized vs. ash sized).
Some volcaniclastic sediments from Frijoles Canyon, New Mexico. The biggest boulders in this image are about 50 cm across. You can see that the big block in the middle made a depression when it landed, we call it a sag. That means the block had to fly through the air ballistically to get there, that is pretty extreme.  
My contribution to the session was to talk about our explosion experiments at the University at Buffalo and how they have helped with the interpretation of layered volcaniclastic rocks from explosive eruptions. There were 17 talks on a range of processes that involved faster or even catastrophic deposition of clastic rocks. These included meteorite impacts, glacial outburst floods, rock avalanches and turbidites (submarine flow of sediment that travels out into the deep ocean). Not only was it a great honor to be invited to talk in a series like this, but also a really great chance to hear about a wide range of specialties and see how much we can learn from research that initially doesn’t sound anything like our own.
Talking about dynamite and volcanoes is one of the best parts of my job.
The conference was hosted in a really neat building in the new town area of Marrakech. The conference included an organized dinner that took us all to the walled city (Medina) to stuff our faces on delicious Moroccan food in a Riad. I was overwhelmed by all the architectural detail of the building.
I loved the mosaic work everywhere.
Look at all the details!
The Riad in old town Morocco (the Medina).

After the formal part of the conference, a group of us went on a field trip to look at landscapes and rocks that are good analogs for the surface of Mars. Mars has active aeolian (wind driven - from the Greek god of the wind, via Latin) processes and evidence of ancient watery environments.
Sand ripples on Earth help inspire good conversations about how ripples and dunes form on Mars.

Even though we were mainly looking for Mars analogs, Morocco has so much awesome geology that we got distracted a few times. The Atlas Mountains are a beautiful example of compressional tectonics having dramatic folds and faults that make geologists drool. Some of the rock formations are so photogenic that many other tourists recognize them from their photos.
Of course we stopped to look at the Pre-Cambrian stromatolites (some of the earliest evidence for life on Earth).

Cool erosional features in the Anti-Atlas mountains. A friend of mine who went on a more traditional tourist trip tells me they are called the "Monkey Fingers."
Vertical bedding, or rocks that were formed horizontally and then through tectonic forces (namely smashing of two continents together) they get deformed and, in this case, turned on end.

Devonian (350-400 million years old) sea critter remains (fossils) were abundant on our trip and a frequent distraction.
Excellent folds preserved in the Atlas Mountains. We spent much of the drive hanging out the windows to photograph the rocks.

We then drove further out into the desert to experience wind transport and deposition first hand. We played in dust storms, climbed dunes, and drove over desert pavement.
Sand dunes in Erg Chebbi, Morocco.
 
Ventifacts, rocks sculpted by the wind dragging sand incessantly across its surface. The rock in the foreground is 2-3 cm thick.  

Mud cracks in fine sand that formed as seasonal ponds between dunes dry up. The 10 Dirham coin is about 4 cm in diameter.

This was my face post ~50 mph or 80 kph winds.


This is what my face looked like while still in those winds. I swear the camels laughed at us.
The group we travelled with came from a variety of backgrounds, including students through senior scientists that studied Earth, Titan, and yes, Mars. We all learned a lot on the trip from the organizers as well as other participants. Field trips of this sort are always a valuable way to get to see rocks with local experts right next to you, but also to get a chance to really get to know new colleagues in a way that is just not possible during the hectic formal conference days.
After you share a dawn camel ride in a severe wind storm with someone you will remember them a lot more than if you just met briefly in a poster session.
If you want to take a geological inspired tour of Morocco there are lots of great suggestions (with coordinates) on the Ibn Battuta Centre website (named for the 14th century traveler of the same name from Morocco). The center exists to help conduct field work in Morocco for geologists, rocket scientists and everyone in between. They did a great job of making our field trip possible and awesome.

If you get a chance to get to some of these spots in Morocco, it is also possible that you will run into packs of geologists staring at rocks.