Welcome to Season 5 Episode 2! In this episode we are talking about rocks, the types of rocks, stones, and humans history with stones.
You can listen to the show here:
As promised here is the famous tweet!
Category: geology (Page 1 of 2)
Welcome back to Borealis Meditation and welcome to season 5! You can listen to the episode here:
Transcript Available here: (work in progress check back soon)
In this episode we talk about the eruption in Tonga on Jan. 15th of Hunga volcano. This eruption was spectacular and in this episode I go over the eruption but also some context in terms of how we monitor volcanoes and tsunami early warning systems.
I have some extra reading for this episode I will put at the end of this post. Also I am working on having transcripts for all my episodes this season. They may take a little time to come out and will definitely be a learning curve but I am working on making my content more accessible.
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Further reading:
NASA post on the eruption: HERE
Global Volcanism Program page for the volcano: HERE (You can read weekly updates on each volcano that has activity)
NOAA Post on this eruption and the future of tsunami research: HERE
An update on the undersea cable situation: HERE
Vulcano is Awake. Does that name sound vaguely familiar? Vulcano, an island and volcano in Italy is where we get the name “volcano”. It is also the traditional home of the God Hephaestus in the Greek pantheon and Vulcan in the Roman pantheon.
In volcanology we often name phenomena and processes after a “type volcano”. Hawaii has given its name to a whole style of eruption along with the name of several flow types and other phenomena. Vulcanian eruptions are named for the style of eruption common at Vulcano, just as Stromboli is the type location for Strombolian eruptions. Plinian eruptions are named for Pliny the Elder a famous intelectual from Rome whose death in the 79 AD eruption of Vesuvius outside of Pompeii was importazlied by his nephew Pliny the Younger. Pliny the Elder is in fact a common source for information on the use and thinking of crystals in the Roman world.
But back to Vulcano. (Volcano specific information provided by the GVP see Resources at the end of the post 1.)
Vulcano is an island and volcano and one of Italy’s Aeolian islands north of the east coast of Sicily. It is in between Mt Etna on Sicily and Stromboli, another island just to its north.
The island itself is made up of several overlapping volcanic features including the two main eruption centers Caldera del Piano (to the SE) and the current center of activity Caldera della Fossa (NW). The island is 136,000 years old and the volcanism has migrated north over time. Vulcanello is a low lava platform that wasn’t connected to the main island until around 1550 CE and was therefore a separate island in the Classical Era.
The last known eruption of Vulcano was in the late 1890s and took place at the La Fossa cone. There are numerous historical eruptions known from the historical record as well as from the rock record previous to that eruption. Since then the only activity recorded in the GVP was in the 1980s and 90s and consists of small earthquake swarms on the island and changes in the intensity, temperature, and composition of the gasses escaping via the fumaroles on the island.
Current activity and unrest on the island began in July 2021.
Let’s take a moment to define that term “unrest”. It basically means a deviation from background levels of activity. Some volcanoes always have some earthquakes and degassing, and others don’t. What is considered unrest at a volcano is specific to that volcano. It basically just means the volcano is doing something different than its normal. So any change in any number of monitored types of activity is considered unrest. Unrest CAN lead to an eruption but it doesn’t always. The activity in the 80s and 90s was unrest but then nothing happened. So we will have to wait and see what this episode of unrest brings.
Since July 2021 the monitoring agency has noted an increase in the temperature of the gasses escaping the volcano at the crater as well as a change in the composition of the gasses. This particular change in gas composition is one that is often linked to the presence of magma in the system. The temperature has increased to 340°C (644°F) and the area where gasses are escaping has increased. In September there was an increase in very small earthquakes (ones that can’t be felt) at the summit as well. Due to all of this the authorities responsible for the volcano closed the summit area on 14 October and there have been some evacuations and reports of animals dying from gases that had made their way into one of the villages on the island.
In an article posted on November 20, 2021 the level of toxic gasses was at an unprecedented level and the civil defense raised the alert level from yellow to orange. There was also talk about evacuating a further 250 inhabitants. The situation has started to rapidly evolve. (4) In a quote from the regional president Musumeci in the article on VolcanoDiscovery (5) he said that “the continued increase in toxic gas emissions recorded by the National Institute of Geophysics and Volcanology in recent days requires the adoption of urgent precautions in order to protect public and private safety, close monitoring of the volcanic phenomena, access restrictions to endangered areas, and the possible evacuation of the population from their homes.” He added that “the government is close to the community and committed to working with the mayor and all other national structures in dealing with the emergency”.
This island is more than the home to the volcano that gave volcanoes their name. It is also traditionally the home of a God. Italian volcanos I find fascinating because they are seen as the “home of” someone rather than an entity on their own (common in more animistic mythos). Italy has a “big four” of volcanoes: Stromboli, Etna, Vesuvius, and Vulcan. Of these, Vulcan is the only one with no eruption in the 20th century onward. Stromboli and Etna are constantly vying for attention and Vesuvius last erupted during WWII. However, it is still Vulcano that is the home to Hephaestus/Vulcan. I thought it would therefore be interesting to take a look at some of the mythology surrounding this island.
Hephaestus is the Olympian god of fire, smiths, craftsmen, metalworking, stonemasonry and sculpture with Vulcan often cited as his Roman counterpart. To me it makes sense that a God of smithing would be associated with volcanoes but I also wanted to talk to some actual blacksmiths about this as well. (6)
According to the theoi.com (6) article on Hephaestus his association with volcanoes comes later in history as the Greeks tended to associate volcanic activity with the Gigante-sons of Gaia instead. It was through his association with the Roman volcano-god Adranus-Volcanus that we get the association with the island of Vulcano. In fact he was originally associated with the Greek island of Lemnos. Later he was associated with the neighboring volcano of Etna on the island of Sicily where his workshop was believed to be located. Etna is also thought to be the prison of Typhoeus (and the activity is thought to be related to the great monster moving and trying to escape). The Vulcano association seems to have happened in the late Roman era when the Romans were culturally integrating the Greek mythic history with attributes of local Gods like Vulcan being associated with Hephastus whose stories would have been told by the Greek settlers on Sicily. So if we were to separate out the two Vulcan has his forge at Vulcano, and Hephaestus seems to have moved around and could be at either volcano (Etna or Vulcao).
However, that is the common association today and is in fact pretty widely known among volcanologists as well. The current myth-understanding is that Vulcano is the forge for Hephaestus/Vulcan.
I spoke with Traci (MythicalMagpie) who is a practitioner who works with Hephaestus in her practice. She was drawn to working with him as a creator, not especially as a smith (although she is interested in trying it). “There was something about […] that he was imperfect. And in his imperfection, he had the strength where he could entrap even the mighty Gods themselves. “ We also spoke about the current activity at the volcano and she said that it got her thinking about what that could have meant to our predecessors. Then we got distracted by this idea of “what is he making”? We looked at the temperature of the gasses coming off the volcano and started looking up melting temperatures of metals.
I also reached out to several smiths. I personally didn’t know any and was interested to hear what they thought.
In chatting with Chris H. of the youtube channel Blood Sweat and Steel we discovered an interesting similarity between volcanoes and forges. I often use the phrase “volcanoes have a personality” to describe how we generally know how volcanoes work but each one really is its own individual. He said forges are similar in that each one has its own personality you have to learn when you start working with it. We ended up speaking about a thead similar to what Traci said drew her to work with Hapheastus. When we were talking about raw materials he said “You’d be amazed at how boring [looking] very valuable things come from.” He also pointed out that while we may have this image in our head of what a forge looks like, those tend to be the older forges and modern forges look “Very disappointing” if that is what you are assuming. I guess that can go hand in hand with volcanoes too. You may picture a nice conical mountain but very rarely are they that perfect, and some are so low angle they just look like lumps or a hill.
I also spoke with Kedrik, who specifically is a goldsmith (winterwolfritualis). He had a traditional master apprentice path into smithing and was also a member of the SCA (Society for Creative Anachronism). He described being in the forge as “Hot, dirty, and gritty. The smithy is a place where earth and fire meet. We organize it and structure it so we can navigate but it is truly a place where a person can plant their feet in the earth and their hands in the flames of creation. There’s a real sense of power but also purpose. And in front of that forge you feel the flame that fuels the relationship.” Which to me sounds a lot like working on volcanoes. When I am working near the summit of a volcano usually there is little to no vegetation and in the tropics that means it is hot and sweaty work. Usually there is still ash on the ground that can easily get kicked up, also making it gritty work. He also sees the symmetry between volcanoes and forge as a place of creation stating “ […] I can see that as the volcano is the vent of the heat that allows life and creation on this planet, and after reading some of Bruce Damer’s work suggesting life came from volcanic vents and hot springs, I can appreciate the parallel of each as a cradle of creation.”
So as this volcano is waking up it may continue towards an eruption or it may just be some heat moving through the system. Hephaestus/Vulcan might just be firing up his forge and getting ready to make something in the crucible of heat that is his forge in a volcano.
I wanted to end with a thought about the importance of place. I asked Traci if it mattered that while the idea that Hepheastus makes his forge at Vulcano is a more modern idea. She said it didn’t bother her that much which volcano it was. “I think there is a part of me that thinks that, […] his home Forge is sacred. This is where a guy goes to find safety, to find purpose, to do the thing that they were created to do. And, and to me, that’s sacred. […] For you know, ancient Greeks it just must have been so incredibly humbling [to see an eruption]. And so the fact that it may or may not have been him himself versus his home, it would still be just as inspiring and humbling to be present.”
I will be keeping an eye on this volcano and updating as more information is available. If you want to keep an eye on the volcano there are two webcams
Thank you to everyone I spoke to for this little project. I wish I could put everything we talked about in here but this is just a blog post. Thank you also to Cory of New World Witchery for peer reviewing the mythology for me and translation help from an amazing Italian volcanologist and friend.
Guests
Traci – Practicing pagan who works with Hephaestus
Twitter: MythicalMagpie
Instagram: mythicalmagpie
Tiktok: @mythicalmagpie
Website
Patreon: mythicalmagpie
Etsy: MythicalMagpie
Chris H. – Polytheist, animist, Celtic Pagan Witch, Devote of Brigid and the Morrigan, and a novice occultist Blacksmith
Youtube: Blood, Sweat and Steel.
Instagram: byhammerandbyanvil
Kedrik – goldsmith, guide, mentor, coach, consultant, and facilitator for personal development practices, esoteric exploration and study, and the creation of totemic relics and jewelry
Store: winter wolf ritualis
Custom work
Wielders Way project
Instagram: cedricwinterwolf , winterwolfritualis
Twitter: metaphystwolf , thewieldersway
Resources
Volcano Information – Global Volcanism Program
Volcano Information from local agency – Here and Here
Mythology Information – Theoi.com
Citations
- Global Volcanism Program, 2021. Report on Vulcano (Italy). In: Sennert, S K (ed.), Weekly Volcanic Activity Report, 13 October-19 October 2021. Smithsonian Institution and US Geological Survey. https://volcano.si.edu/volcano.cfm?vn=211050
- Aeolian Islands, worldatlas.com https://www.worldatlas.com/islands/aeolian-islands.html
- Bonadonna C, Frischknecht C, Menoni S, Romerio F, Gregg C E, Rosi M, Biass S, Asgary A, Pistolesi M, Guobadia D, Gattuso A, Ricciardi A and Cristiani C 2021 Integrating hazard, exposure, vulnerability and resilience for risk and emergency management in a volcanic context: the ADVISE model Journal of Applied Volcanology 10 7 https://link.springer.com/epdf/10.1186/s13617-021-00108-5
- Vulcano, ora è stato di emergenza per gas tossici. “La situazione è inedita”, cresce l’allerta sull’isola, newsicillia.it https://newsicilia.it/messina/cronaca/vulcano-ora-e-stato-di-emergenza-per-gas-tossici-la-situazione-e-inedita-cresce-lallerta-sullisola/729395
- VolcanoDiscovery Updates https://www.volcanodiscovery.com/vulcano/news/148026/Vulcano-volcano-Eolian-Islands-Italy-alert-level-raised-as-gas-concentrations-in-port-reach-critical.html
- Theoi.com https://www.theoi.com/Olympios/Hephaistos.html#Index
https://www.theoi.com/Olympios/HephaistosGod.html#Volcano
Listen to the episode here:
In this episode we go over the main parameters used to identify different minerals. These would be:
- visual
- color
- luster
- mineral form
- streak color
- physical properties
- hardness
- density or specific gravity,
- mineral structure related
- cleavage
- fracture
- other identifying characteristics
- taste
- smell
- magnetism
- fluorescence
- radioactivity
- reactivity
Music in this episode was played by permission and is by Aazav and SJ Tucker
Listen to the episode here:
In this episode I answer questions from both the reddit /r/SASSWitches and from submitted from listeners. The episode starts with a bit of an overview of working in academic research to give a bit more context to why my job is. I hope you enjoy and I am always open to answer any questions.
I brought up one of my favorite historical geologists Nicholas Steno
My husband also sent me this comic called “How people in science see each other” I have excerpted it here but it links to the full version.
The book I recommended for getting into witchcraft is Paganism for Beginners: The Complete Guide to Nature-Based Spirituality for Every New Seeker by Althaea Sebastiani. I highly recommend this book and this author for everyone especially those new to this path.
The other book I mentioned was Venus and Aphrodite by Bettany Hughes which I listened to on Audible.
Music in this episode is used by permission of the artists
List to the episode here:
Show notes:
Music included in episode
Fold of Evening by Aazav
Iron from Stone by Damh the Bard
Here are some of the definitions we discussed and links to the quotes I used for each section.
Element:
Elements are atoms, the smallest piece that we can split matter into (except for subatomic particles and other things that we’ll leave to the physicists). Different elements have different properties. Take two different elements: iron and helium. Iron is very different than helium. You wouldn’t fill a balloon with iron any more than you would try to build a bridge out of helium. (ASU)
A solid can be made of a single element, and as we will see that is not a mineral. The elements that are known are all listed in the Periodic table. They have different properties and are defined based on the number of protons and electrons. Periodic Table
Mineral:
Minerals are materials that meet five requirements. They are:
1. naturally occurring,
2. inorganic,
3. solids,
4. with a definite chemical composition, and,
5. an ordered internal structure
(geology.com)
or from mindat.org an “informal but practical definition”
A mineral is a chemical element or compound that:
1. has a more-or-less constant composition.
2. is usually a solid with an ordered three dimensional array of ions and molecules in its crystal structure.
3. is formed by natural geologic processes and without human or other biologic intervention.
4. is not a mixture of two or more blended substances.
(mindat.org)
The ordered internal structure is also called the “Crystal Structure”
“Crystal structure is a continuous ordered arrangement of one or more elements. This is simply a fancy way of saying that minerals are composed of elements that are stacked in an orderly and neat fashion. You can think of elements as different sized marbles (except, in this case, the marbles are all very, very tiny!). Based on the relative sizes of the marbles, they can be stacked in different ways […].
A good example of a simple mineral is table salt (Yes, salt is a mineral.). The proper mineral name for table salt is halite, and a geologist will often identify it by tasting it. Salt is composed of two elements; Sodium (Na) and Chlorine (Cl). Sodium and chlorine are strongly attracted to each other and stack together into a cubic crystal structure (see figure). Individual salt (halite) crystals have a cubic shape to them, which is mimicking the way that the individual elements are stacking together. Even though the elements are much too small to be able to see with your eyes (or even most microscopes), you can tell how they are stacking together by looking at the shape of the salt crystals.”
(ASU)
“Most importantly, [a mineral is something that] has been exhaustively studied and characterized by mineralogists, declared unique in its composition and structure, and the original specimen(s) that was studied deposited for preservation in a professionally curated museum.” (mindat.org)
Resources:
MinDat
WedMineral
Mineraloid:
“A mineraloid meets almost all of the criteria of a mineral except the organized structure. Some can also lack the definite chemical composition. Minerals as we talked about are “crystalline” meaning they have an organized structure. Because mineraloids are “amorphis” they do not have an order structure. I think this is better explained with examples. Opal, obsidian, pele’s hair, and tektites are all mineraloids. Now the last few are types of natural glasses where because of the heat and the quick cooling no crystals are able to form.” (Geology.com)
There is some controversy if organic materials can also be included. Remember that part of the definition of a mineral was that it was non-organic. This means some people include things like amber and jet as a mineraloid and others don’t. Jet is a type of coal which is made from plant material like leaves and amber is from plant resin. Also there are materials that are made in the deep ocean from the “ooze” made up of tiny organisms like diatoms and radiolarians shells called diatomite and radiolarite. For our sake I think we should also consider these mineraloids since they also lack an organized structure.
So in that case a mineraloid is a solid, naturally occurring material without a defined interior structure and may or may not have a defined chemical composition, generally inorganic but some organic materials can also be included.
Anthropogenic substances:
“Anthropogenic substances are those produced by humans. They are not minerals. Crystals grown in a laboratory (or someone’s basement) or in laboratory or industrial furnace or retort are not minerals. Any crystals that are found on or in any man-made object are not a mineral.” (mindat.org)
Rocks:
“A rock is any naturally occurring solid mass or aggregate of minerals or mineraloid matter. It is categorized by the minerals included, its chemical composition and the way in which it is formed. Rocks are usually grouped into three main groups: igneous rocks, metamorphic rocks and sedimentary rocks.” (wikipedia)
“A rock is not a mineral, nor is a mineral a rock. However, the components of a rock are minerals. Most types of rock have multiple minerals, a few have only one. Single mineral rocks are termed monomineralic rock.” (mindat)
Igneous Rocks:
An igneous rock starts out purely as a melt. Everything is liquid and all the elements are there swimming around. Then it starts to nucleate minerals, some start growing before others and use up all the elements they want. It can either cool slowly and all the crystals will grow into an interlocking solid material like a granite, or can be brought to the surface and erupt and cool quicker with some small crystals and the melt freezing not having totally formed crystals. Obsidian is the extreme of this where basically no crystals have had time to form and the melt is just frozen. Of course it is a little more complicated but we can go into that another time.
Sedimentary Rocks:
Sedimentary rocks are formed when the rocks at the surface break down either physically by breaking apart into smaller pieces or chemically. These small bits can be redeposited and smoshed and get cemented together and this forms our sedimentary rocks. Generally speaking when a rock physically breaks apart you can end up with either pieces with several minerals, or a single crystal and anywhere in between.
Metamorphic Rocks:
Metamorphic rocks can be formed from either sedimentary or igneous rocks. These are rocks where the original rock is subjected to higher levels of pressure and temperature and the minerals can start to change into other minerals. This can happen to a small or large degree and rocks can also start to flow and make cool patterns. Then this smooshed and heated rock is brought back to the surface for us to marvel at. The minerals in the original rock can change their composition and/or structure at these different conditions so one rock can be turned into multiple different types depending on how much pressure and temperature it experienced. Some minerals are only formed through this process.
Crystals/Gems:
Safety information: gem society
“A crystal is a regular polyhedral form, bounded by planes, which is assumed by a chemical element or compound, under the action of its intermolecular forces, which passing, under suitable conditions, from the state of a liquid or gas to that of a solid. A crystal is characterized first by its definite internal molecular structure and second, by its external form.” (mindat)
From merriam-webster:
1. a clear, transparent mineral or glass resembling ice.
2. the transparent form of crystallized quartz.
“A crystal consists of matter that is formed from an ordered arrangement of atoms, molecules, or ions. The lattice that forms extends out in three dimensions. Because there are repeated units, crystals have recognizable structures. Large crystals display flat regions (faces) and well-defined angles. Crystals with obvious flat faces are called euhedral crystals, while those lacking defined faces are called anhedral crystals. Crystals consisting of ordered arrays of atoms that aren’t always periodic are called quasicrystals. The word “crystal” comes from the Ancient Greek word krustallos, which means both “rock crystal” and “ice.” The scientific study of crystals is called crystallography. “ (thought co)
So then what is a gem?
“A gem is a rare mineral that is prized and used in jewelry.” (differencebetween.net)
“difference between gem and crystal is that gem is a precious stone, usually of substantial monetary value or prized for its beauty or shine while crystal is (countable) a solid composed of an array of atoms or molecules possessing long-range order and arranged in a pattern which is periodic in three dimensions.” (WikiDiff)
“A gemstone is a crystalline mineral that can be cut and polished to make jewelry and other ornaments. The ancient Greeks made a distinction between precious and semiprecious gems, which is still used. Precious stones were hard, rare, and valuable. The only “precious” gemstones are diamond, ruby, sapphire, and emerald. All other quality stones are called “semiprecious,” even though they may not be any less valuable or beautiful.” (ThoughtCo)
I will be making a formatted reference post shortly as a quick guide. Let me know if you have any questions!
Welcome to a conversation about the concept of Deep Time. Deep time is basically geologic time but the concept is so much more complex when trying to internalize.
I hope the many examples and repetitions help you start to understand this concept and how it can be beneficently within your practice.
I would love to continue the conversion in the comments or on twitter @katborealis
I have several recommendations for reading and listening:
Timefulness
This is the book I recommended on the topic of Deep Time. The first part is one of those books where when you are reading it you feel like “I wish I had written this!”
Timefulness: How thinking like a geologist can help save the world by Marcia Bjornerud
Dan Carlin
I have been listening to Dan Carlin for YEARS like… more than I want to say because it makes me feel old. He is super into the human experience in the past. His recent book has an excellent chapter on pandemics and his has an old episode on the topic as well.
Dr. Robin Wall Kimmerer
I don’t know what to say other than I LOVE her!
I don’t know what to say about this book other than I just love love love this book! My copy has so many underlines. This is where I got the accelerating climactic chaos! Much better than Climate Change.
John McPhee
John McPhee is Mr Geology writing I think is fair to say. He is amazing to read but not a page turner. I have a few recommendations:
This was a very influential book for me. The topic of this one is humans vs. nature. Humans trying to control the uncontrollable.
There was no activity reported for Pagan Volcano this week, so we are going to look at the island itself this week. I think Its an excellent example of an island arc volcano. 
This is a diagram of an island volcanic arc. See? We are back to the structure of the earth, like I said its always important. In order to produce an island volcanic arc, you will have an oceanic/oceanic subduction zone. The oceanic crust that is subducted is the older thicker and denser of the two oceanic plates.
Once the older oceanic crust is subducted to around 100km the water will be driven out of the rocks and lower the melting temperature of the surrounding mantle. That is the 101 explanation of what is going on and is pretty accurate. This produces melt that becomes buoyant and rises. When this magma breaks through to the ocean floor it starts to build volcanoes.
Once these volcanoes start to build they produce underwater eruptions until they have built up enough mass to break the ocean surface. Then it starts to build islands. These islands are volcanic arcs.
That is how Pagan Volcano was built.
As you can see Pagan Island is part of a chain of volcanic arc islands that sit above the subducting Pacific plate as it dives under the Philippine Sea Plate. The Mariana trench is also home to the deepest point on the earth the Challenger Deep. It is 10,898 m (35,755 ft) to 10,916 m (35,814 ft) below sea level.
Here is Pagan Island rising from the seafloor with a vertical exaggeration of 3
Next time we will talk about the island itself and how it formed!
References, more reading and image sources
1 http://blue.utb.edu/paullgj/physci1417/Lectures/Plate_Tectonics.html
2 http://www.sciencedirect.com/science/article/pii/S0012821X08005529
3 http://www.soest.hawaii.edu/pibhmc/pibhmc_cnmi.htm
Pagan Island Wikipedia page
Mariana Trench Wikipedia page
Volcanic Arc Wikipedia page
Listen to Episode 3 here
Show Notes:
Geo 101 section:
– Earths structure, compositional boundaries, rheology boundaries and using seismology to figure it all out!
Ray paths of EQs through the earth note the bending in the outer core and the way it creates a gap on the surface that is the P-wave shadow!
Travel time curve poster from IRIS (group of seismology organizations) the colored dots are arrivals time is on the vertical axis and degree distance is on the horizontal axis.
Feature Mineral:
– crystal systems
– quartz (general)
(blog posts are here and here )
Ramblings:
old ass rock article
pristine mantle from earths formation!
BBC and MSNBC articles
weekly update
The secret to life may be as simple as what happens between the sheets — mica sheets
detailed notes will be available in the next few days so check back!
Geo-news:
– photos of the uplifted coastline from the earthquake in Chile.
“Earlier this year, the 8.8 quake that hit Chile did more than level homes. It raised the ocean floor so much that undersea regions broke the surface of the water. Here are pictures of Chile’s incredible new coastline.”
subduction zones when locked can deform the overriding plate and when the stress is released the plate “slaps” back down, and other places rise up. depends on where in the bulge you are! there are drowned forest on the coast of Washington from the last release in the Juan de Fuca subduction zone, that area dropped enough for salt water to get into the roots and kill the tress. Same thing happened in the ’64 quake in Alaska. However its not all dropping. closer in you can get uplift. Think of it this way, if you take a ruler and push down on one end, you get a depression but a little further back it buckles up into a hump. so when that stress is released part goes up (back to original position) and part goes down (back to original position). These coastlines in Chile went up! I hope that made sense. Its the same physics in both cases the uplift and down dropping.
– Map for aspiring diamond hunters!
for articles about the research click here and here
I saw this talk at a conference last year!
though not mentioned much in the write ups on this study I believe that, this study is looking at a low velocity zone in the earth and inferring that the edges of these large low velocity zones are where you get mantle plumes, and that in order to get diamonds on the surface you need something like a mantle plume to punch through the whole crust and bring them up. On the next podcast I am going to talk about earth structure and a little bit about seismology and how it was used to determine earths structure. the map is a map of % changes in velocities of seismic waves (how we map things we can’t see) I am pretty sure there was something on this in one of my other podcasts I listen to so I’ll find it and post a link below!
Nature podcast episode its the first story! clicking should download the episode if not
its the July 15, 2010 episode
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