4.7 quake right in the Toba supervolcano caldera... ruh roh

Originally posted by poet1b

What concerns me is that warming oceans are raising ocean levels, so what effect are these pressure having on the crust.

The Earth gets warm, oceans heat up, waters expand, super volcanos erupt.

These increases in planetary hydraulic pressures could move a lot of things around.

not to mention the constant removal of oil from the crust..if im not mistaken oil is a lubricant. kind of helps moving parts even before we take it out of the ground. it doesn't surprise me if things grind more without lubricant.

First time I see an event, inside the Toba Caldera, in nearly 15 years watching seismic activity, every morning when I arrive at work, at Sumatra. But 15 years is nothing of course.

Otherwise.

It's volcanic winter and not nuclear winter boys. And a decade, if it was or would be only a decade, of volcanic winter is a very long period when you have to eat and drink every day.
When you see the death toll in Europe, famine, after moderate eruptions in the past it makes me wonder how big the death toll, worldwide would be after a big VEI 7 (500+ km3 tephra ejected) or a VEI 8.

Originally posted by poet1b
reply to post by eriktheawful

 

So what was your unrelated fish tank example, your statement on simply adding water, and your link about heating water makes it less dense about? All of them had no relation to what I was stating, and you failed to recognize that thermal expansion was raising the sea level.

Now that I proved your points inapplicable, after I have proved thermal expansion of deep ocean waters is raising sea levels, meaning increase pressure, and therefore pressure on the continents, you dismiss it without any evidence provided on your part. Now after making your inapplicable argument, way off base, you still insist you are right without anything to back up your claims.

Where is your proof that planet Earth is so solid that something like deep ocean pressure couldn't affect the rim of fire?

Being that there are Earthquakes and volcanic eruptions, things aren't as solid and stable as you claim.

The fact is that it is very possible that increase ocean pressure could in fact upset the delicate balance that keep the surface of the Earth stable. If a tsunami can change the tilt of the Earth's axis, what could increased deep ocean pressure do? It is in fact very possible.

The reason I've not provided any thing to back up what I'm claiming is because it should be common sense. Since it seems I was wrong about it being common sense, I'll attempt to explain why:

First let us review your claim:

You've stated that you believe that increases in ocean pressure due to the volume of water increasing, either by the addition of water and/or from thermal expansion of that water, is enough pressure to affect geology, such as shifts in faults and the eruptions of volcanoes.

My argument against your suggestion is based upon several things.

1) Water has a average density of 1.0 g/cm^3, where as rock has densities well above that. One square foot of rock will mass much more than 1 square foot of water. While it's true that water can cut, carve and erode rock over time, it takes a massive amount of water to actually move rocks. One mile in depth of water, the pressure can be great. But the pressure of 1 mile of rock would be much greater. People seem to think that the oceans are so vastly deep, and compared to us, they are. But compared to the Earth itself, oceans are actually a very thin layer:



2) The Earth is solid below the crust. The Mantle of the Earth is not liquid:

It is predominantly solid and encloses the hot core rich in iron and nickel, which occupies about 15% of Earth's volume.[2][3] Past episodes of melting and volcanism at the shallower levels of the mantle have produced a thin crust of crystallized melt products near the surface, upon which we live.

We know this by measuring the speed at which Earthquake waves travel:



I believe the solidity of the Earth because that's what science says is down there.

3) The amount of pressure at the bottom of the Mariana Trench, the deepest part of any ocean, is about 16,000 PSI. That pressure is from the weight of the water due to the amount of volume (depth) and gravity. Where as the pressure on fault lines and plate subduction is measured in the millions of PSI.

So again: even if all the ice on the Earth were to melt and even if the oceans were to have their temperatures raised by 10 degrees, the volume increase is not enough to exert enough pressure on the Earth's crust to make fault lines move, make subduction happen faster, or make volcanoes erupt. The pressure from the water depth is simply not enough for that.

By the way: the Earth's axis was not moved by a Tsunami. Our axis has been moved by plate tectonics or earthquakes. Not by a large wave of water.

reply to post by Foxy1


I'd have to agree with your lubrication theory. It is strange that there also seems to be oil reserves around the fault lines. The oil and gas can also fuel the reaction though, something to consider. It may be beneficial to remove gas deposits from around volcanoes.

I thought we were keeping an eye on this thing? Tellin yas, I can't be posting much anymore or watching cause of work, so need yas to take up my slack for a while. Another 4.8 quake has occurred, some 90-100 km from the caldera. And normally I wouldn't be concerned, but look at the shallow depth of 10 km of that quake. That depth doesn't appear to be a subduction-caused quake, because at that spot it should be MUCH deeper. But it isn't. So hope it a shallow fault. Because if it isn't, then...

earthquake.usgs.gov...

reply to post by eriktheawful


First, I will state my claim.

Warming of deep water ocean is causing expansion which is increasing the sea levels.

This expansion of deep water is increasing pressure that not only pushes up against the surface of the ocean, but also against the continental shelve, and could possible upset the balance between the tectonic plates and and the upper mantle, leading to an increase in earthquake activity and possibly volcanic activity.

This isn't common sense stuff, this extremely complicated, and your simplistic application doesn't address the issue at all.

Density does not mean that the forces of hydraulics do not push things around. Deep ocean pressures will crush hulls made of the strongest metals known to man, metals far stronger than the granite that makes up most of the continental crust. Density in not an indicator of material strength in resistance to force.

Your claim that ocean pressure does not shape the Earths crust, or can contribute to Earthquakes or volcanic activity overlooks numerous facts.

First of all, the weight of the ice in Antarctica alone, actually pushes down the continent.

www.doc.ic.ac.uk...

The weight of the Antarctic ice is so great that in many areas it actually pushes the land below sea-level. This process of the earth's crust being deformed is known as isostasy. Without its ice cover Antarctica would eventually rise up another 1500 feet (450 m) above sea-level.

The amount of water on Antarctica is tiny compared to the amount of water in the oceans.

The Earth's crust isn't a solid shell of rock like an egg shell, it is a broken, fissured, and shattered structure, that is constantly moving, large shelves push against each other.

In this link there is an interactive table that allows you to see where the different types of plate boundaries exist. Notice the divergent boundaries are all in the middle of the ocean, with one exception, along the CA coast.

www.learner.org...

Here is an illustration.

www.worldatlas.com...



This is what is happening with divergent boundaries.

geography.about.com...

Divergent boundaries are where the plates move away from each other and new crust is created. Mid-ocean ridges are an example of divergent boundaries.

The location of the divergent boundaries in the oceans are a strong indication that the hydraulic pressure created by the ocean depths does in fact shape the planet, and influence tectonic movement.

reply to post by poet1b


Continuing on, ran out of space.

This link puts the complexities in perspective.

jersey.uoregon.edu...

It seems certain that the earth rapidly gets hotter as you go deeper into the crust, and soon reaches a temperature where even the rocks will melt. We call the liquid form of rock "magma," in the same way that we call the liquid form of ice "water." In simple terms, the earth is just a large ball of magma which has crystallized into solid rock where it's exposed to the coldness of space. The stuff inside isn't really a "liquid" (the pressure is far too great for that), but whatever is down there probably isn't a "solid" either, at least as we understand the term here on the surface. Because of this semi-rigid plastic state, atoms, ions and other particles can ooze around (albeit very slowly).
...
Poorly understood forces cause these rigid crustal plates to move, relative to each other, over the higher density plastic material which is thought to occur beneath the crust. Tectonic activity (earthquakes, volcanoes, and mountain building in general) is common at plate boundaries, where the edges of two (or more) plates are in contact along huge linear zones of faulting. Plate tectonics is the study of these crustal slabs, and how they interact at their edges. Three (3) relative motions are possible: pulling apart, crashing together, and sliding side-to-side against each other. This is because different plates move at different velocities, ranging from one (1) to greater than ten (10) centimeters per year. This may not seem like much, but over the course of geologic time it can have profound effects. With the help of friction and Newton's 1st Law of Motion, the earth does its best to keep the edges of the plates from slipping. But, as the plates continue to move and stress along the fault increases to the breaking point, the fault will rupture, the accumulated strain will be released in a seismic event (earthquake), and the plates will shift along the boundary... only to lock-up again and begin the process anew. The amount of energy involved here is immense beyond our ability to comprehend, and surely beyond our ability to restrict or control. All we can do is study the process, try to keep out of the way, and, if we can't, hang on tight.
...
Working together, the spreading and subduction processes make for a great global balance (the earth is really into balance and is good at it - it's been practicing for a very long time). New basaltic crust is produced at the spreading centers, and then consumed (or eaten, if you will) at the subduction zones, where it is purified and converted into granite. This is a real good thing, too! Without both processes the earth would either expand like a balloon (and pop?), or it would eventually eat itself into non-existence. Either result would cause problems for those of us destined to exist on its surface.

The question remains, can increasing deep water ocean pressure upset this balance.

reply to post by MamaJ


Just because one scientist disagrees does not make it a consensus, not that we should ever deal in consensus science. If it did AGW would be a lie..........mmm

Don't forget also the little published fact that Toba lake has been getting warmer............

reply to post by poet1b

The question remains, can increasing deep water ocean pressure upset this balance.

In a nutshell no.

Bear in mind that any increase on ocean levels gives a corresponding decrease in land weight, and bear in mind also that the weight of additional water is spread out much further than on the land from whence it came. The weight is insignificant, however it is a fact (that TA does not agree with) that pressure, and pressure changes, can cause localised earthquakes when for example there is a major depression such as a hurricane. It is also a fact that every year the change in ice mass in places like Iceland leads to earthquakes.

Then consider the density of water and the density of rock. At the very least rock is 3 times as dense as water thus the pressure from the rock overburden is considerably greater than that from water. Water at best only goes to ~11km deep and that is in a very narrow band about 2500 km long and 70km wide. (Mariana Trench).

The average depth of the oceans is ~4000 metres (4 km or 12,000 feet). The average depth of the mafic crust of the lithosphere is 5km - greater than the water @3 times the density, and the lithosphere, depending on where you measure is 50 to 100km thick or more.

That still leaves ~6300km to go to the centre of the earth.

Even if all the ice caps melted - giving a rise of ~100 metres (0.1km) this is not a significant amount in terms of pressure on the crust, and has the added benefit that my house would become a seaside property! (Chosen specifically for that reason)


ETA: Just read erictheawful's answer. Yes - I concur.

Originally posted by westcoast
I remember watching that swarm Mamaj ... nervously. If I recall correctly (scary), I believe those never got any closer than off-shore, along a known fault.

As to the new 'evidence', claiming that the extinction event never happened; while interesting and certainly cause for further exploration, I don't think it is by any means conclusive. It is like saying that because the needle wasn't found in this handful of the haystack, than it simply doesn't exist.

We have some pretty good historic (geological) records of what happened when Yellowstone went off, and we know that Toba is bigger. So, no matter what did or did not happen in the past, I believe that the potential for a planet killer event is there.

Let's hope its another 75,000 years before we find out.

I just want to come back to this.

I'm not saying it wasn't a devastating event, worldwide, and hard times for our ancestors but I don't buy in the bottleneck extinction theory because of the Taupo VEI 8 eruption 26 500 years ago.

Even if the toba eruption was 2 to 3 times bigger than the Taupo one, both should have triggered a volcanic winter and the mentioned global cooling. The theory says Toba did but why isn't there any evidence for the Taupo one that's much closer to us.

Just a fishy feeling here but I'm sure we're missing some key clues to have a more accurate picture of what really happened back then.

earthquake.usgs.gov...

Another 4.3 right in the Toba caldera?

Wassa matta with you people?

Fine... Perish, you fools when the big daddy blows up in your faces.

Lucky for joos it was 148 km deep. THIS time.

reply to post by TrueAmerican


Wah...I'm only just up Boss! I did watch it for a couple of days, and as soon as I nod off, there you have it. Ok so it's deep, but it's still Toba, and still an earthquake. I'm off to buy more beans. Thank you again for the post.

reply to post by TrueAmerican


In the past month:

Prov,Date/Time UTC,Latitude,Longitude,Magnitude,Depth(Km),Location
emsc,2013-07-19 06:36:22, 2.398, 98.876, 4.5, 143.0, Northern Sumatra Ind.
emsc,2013-07-11 07:16:26, 1.838, 99.162, 4.7, 10.0, Northern Sumatra Ind.
emsc,2013-07-09 01:05:39, 2.246, 96.230, 4.8, 25.0, Simeulue Ind.
emsc,2013-07-05 16:54:39, 2.572, 98.670, 4.8, 5.0, Northern Sumatra Ind.

I don't think the last one is connected. That is a subduction quake.

Click for a larger version

The spread for the one month list is over the box Lat 1 - Lat 3.5, Lon 94 - Lon 100

A 1 degree spread around the caldera (Lat 2 to 3, Lon 98.25 to 99.25) for the last 1000 days gives this list (from EMSC which have 1 more than USGS)

Prov,Date/Time UTC,Latitude,Longitude,Magnitude,Depth(Km),Location
emsc,2013-07-19 06:36:22, 2.398, 98.876, 4.5, 143.0, Northern Sumatra Ind.
emsc,2013-07-05 16:54:39, 2.572, 98.670, 4.8, 5.0, Northern Sumatra Ind.
emsc,2013-02-09 02:50:39, 2.306, 99.063, 4.6, 161.0, Northern Sumatra Ind.
emsc,2012-09-29 20:19:08, 2.454, 98.437, 4.8, 99.0, Northern Sumatra Ind.
emsc,2012-08-27 09:01:24, 2.428, 98.999, 5.2, 157.0, Northern Sumatra Ind.
emsc,2012-05-08 22:23:50, 2.003, 98.877, 4.7, 128.0, Northern Sumatra Ind.
emsc,2012-03-12 21:43:35, 2.758, 99.113, 4.4, 175.0, Northern Sumatra Ind.
emsc,2011-07-31 23:17:56, 2.550, 99.070, 4.6, 161.0, Northern Sumatra Ind.
emsc,2010-12-17 12:42:32, 2.800, 98.870, 4.5, 158.0, Northern Sumatra Ind.
emsc,2010-12-01 00:50:22, 2.690, 99.010, 5.5, 165.0, Northern Sumatra Ind.

Virtually all of these are deep quakes and thus subduction and not faulting in the caldera itself.

IMO nothing happen at present, but of course Toba is always an area to keep an eye on.

Originally posted by poet1b

What concerns me is that warming oceans are raising ocean levels, so what effect are these pressure having on the crust.

The Earth gets warm, oceans heat up, waters expand, super volcanos erupt.

These increases in planetary hydraulic pressures could move a lot of things around.

I've been thinking about warming effect too, that maybe the melting ice-caps are also contributing to EQ activity? Less ice = less weight, and the land it sits on would be less compressed and spring back up causing the edges of the plate to move. Could this in turn cause the adjacent plates to move along with it?

reply to post by doobydoll


Samuel L is that you?

Originally posted by Senduko
reply to post by doobydoll

 

Samuel L is that you?

I'm not Samuel L, sorry.

But I have to say that when I read your post it stopped me in my tracks because I had a fleeting sense of recognition and had an urge to say yes. It felt really weird.

reply to post by doobydoll


Most of the post glacial rebound occurred thousands of years ago and contributed to some major earthquakes that were not plate related, and to volcanic activity particularly in Iceland.

Glaciation is NOT the norm for the planet. You CANNOT maintain a status quo of ice when ice is not actually the normal state of the planet.

Have a read of [utl=http://en.wikipedia.org/wiki/Quaternary_glaciation]Quaternary glaciation[/url] in Wikipedia, however I take issue with them that 'global warming' has exacerbated the retreat of the glaciers because that statement is highly inaccurate. The world is warming, naturally, and that has caused the glaciers to retreat, as opposed to exacerbated the retreat, and the ice caps to melt because we are in an interglacial period.

I believe what they are trying to imply is that AGW has exacerbated the retreat, but that is not what they stated. Wikipedia can be very inaccurate sometimes. That is a completely different issue.