In the deep sea, the last ice age is not yet over

Gas hydrate deposits in the Black Sea react to post-glacial climate changes

HELMHOLTZ CENTRE FOR OCEAN RESEARCH KIEL (GEOMAR)

Research News

IMAGE
IMAGE: DRILL CORES FROM THE MARUM-MEBO200 ARE RECOVERED ON DECK OF THE RV METEOR. view more CREDIT: CHRISTIAN ROHLEDER.

Gas hydrates are a solid compound of gases and water that have an ice-like structure at low temperatures and high pressures. Compounds of methane and water, so-called methane hydrates, are found especially at many ocean margins – also in the Black Sea. In addition to a possible use as an energy source, methane hydrate deposits are being investigated for their stability, as they can dissolve with changes in temperature and pressure. In addition to releases of methane, this can also have an impact on submarine slope stability.

During a six-week expedition with the German research vessel METEOR in autumn 2017, a team from MARUM and GEOMAR investigated a methane hydrate deposit in the deep-sea fan of the Danube in the western Black Sea. During the cruise, which was part of the joint project SUGAR III “Submarine Gas Hydrate Resources” jointly funded by the BMWi and BMBF, the gas hydrate deposits were drilled using the mobile seafloor drilling device MARUM-MeBo200. The results of the investigations, which have now been published in the international journal Earth and Planetary Science Letters, have provided the scientists with new insights into changes in the stability of gas hydrates.

“Based on data from previous expeditions, we selected two working areas where, on the one hand, methane hydrate and free methane gas coexist in the upper 50 to 150 metres of the hydrate stability zone and, on the other hand, a landslide and gas seeps were found directly at the edge of the gas hydrate stability zone”, explains Prof. Dr. Gerhard Bohrmann, expedition leader from MARUM and co-author of the study. “For our investigations we used our drilling device MARUM-MeBo200 and broke all previous depth records with a maximum depth reached of almost 145 metres”.

In addition to obtaining samples, the scientists were, for the first time, also able to carry out detailed in situ temperature measurements down to the base of the gas hydrate stability under the seabed. Previously, this baseline was determined using seismic methods, from which the so-called “bottom simulating reflector” (BSR) was obtained as an indicator of this base. “However, our work has now proven for the first time that the approach using the BSR does not work for the Black Sea”, explains Dr. Michael Riedel from GEOMAR, lead author of the study. “From our point of view, the gas-hydrate stability boundary has already approached the warmer conditions in the subsurface, but the free methane gas, which is always found at this lower edge, has not yet managed to rise with it”, Riedel continues. The reasons for this could be attributed to the low permeability of the sediments, which means the methane gas is still “stuck” down there and can only rise very, very slowly under its own power, according to the scientist.

“However, our new analyses of the seismic data have also shown that in a few places the methane gas can break through the BSR. There, a new BSR is just establishing itself over the ‘old’ reflector. This is new and has never been seen before”, says Dr Matthias Haeckel, co-author of the study from GEOMAR. “Our interpretation is that the gas can rise in these places, as disturbances in the seabed here favour the flow of gas”, Haeckel continues.

“In summary, we have found a very dynamic situation in this region, which also appears to be related with the development of the Black Sea since the last ice age”, says Michael Riedel. After the last glacial maximum (LGM), the sea level rose (pressure increase), and when the global sea level rose above the threshold of the Bosporus, salty water from the Mediterranean Sea was able to propagate into the Black Sea. Before that, this ocean basin was basically a freshwater lake. In addition, global warming since the LGM has caused a temperature rise of the bottom water in the Black Sea. The combination of these three factors – salinity, pressure and temperature – had drastic effects on the methane hydrates, which decompose as a result of these effects. The current study exemplifies the complex feedbacks and time scales that induce climate changes in the marine environment and is therefore well suited to estimate the expected consequences of today’s more rapid global warming – especially on the Arctic gas hydrate deposits.

Cruise leader Gerhard Bohrmann summarizes: “At the end of the SUGAR-3 programme, the drilling campaign with MeBo200 in the Black Sea showed us once again very clearly how quickly the methane hydrate stability in the ocean deposits also changes with environmental fluctuations”.

###

Reference:

Riedel, M., T. Freudenthal, J. Bialas, C. Papenberg, M. Haeckel, M. Bergenthal, T. Pape, and G. Bohrmann, 2021: In-situ borehole temperature measurements confirm dynamics of the gas hydrate stability zone at the upper Danube deep sea fan, Black Sea. Earth and Planetary Sci. Lett., https://doi.org/10.1016/j.epsl.2021.116869.

Links:

http://www.gashydrat.de Gas hydrate research at MARUM

https://www.sugar-projekt.de/sugar SUGAR Project

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Ron Long
March 31, 2021 2:54 am

This appears to be another example of some good field work, by scientists, generating some interesting and potentially useful data, but mixing it with CAGW political correctness, such as “…estimate the expected consequences of todays more rapid global warming…”. So they are either chasing after funding or unicorns.

Willem69
March 31, 2021 3:23 am

Ah yes, gas hydrates. Been reading about those for the last 25 years. First as a potential resource and more lately as another of earth’s ticking time b0mbs on the way to climate doom.

Best thing would be to mine them and convert the methane to CO2 to prevent the climate apocalypse.

i wonder how many carbon credits i would get for such a project?

Stay sane,
Willem

Scissor
Reply to  Willem69
March 31, 2021 5:49 am

Practically speaking, natural gas pipeline engineers and technicians have been dealing with them for many decades.

dodgy geezer
March 31, 2021 3:43 am

In the deep sea, the last ice age is not yet over…

Er… we are STILL IN an ice-age. I thought it was defined as a period where there was all year-round ice at sea level somewhere on the planet.

We are in an ‘interglacial’ at the moment – a period when ice retreats and does not completely cover the planet, but it will come back again shortly (geologically-speaking, that is). The last I heard, the short warm periods were nick-named ‘hothouses’. We are certainly not in one of those…

Robertvd
Reply to  dodgy geezer
March 31, 2021 9:56 am

Yep. If we look at the last 200 Ma the recent 3 Ma have been the coldest. Life on Earth has absolutely no problem with a warmer planet.

AndyHce
Reply to  dodgy geezer
March 31, 2021 4:33 pm

It all depends upon your political philosophy/ideology.

Vuk
March 31, 2021 4:48 am

Inter-glacial hospitality period is very short, judging by most of the past indicators we have overstayed our welcome.
On more imminent scale the SC25 sunspot cycle is picking up but is reluctant to take off, pointing to a longer and below average strength cycle.

SSN-3-minima.gif
Sunsettommy
Editor
Reply to  Vuk
March 31, 2021 9:33 am

Actually Vuk, the planet has been slowly sliding towards Glaciation for thousands of years now.

The peak warmth was around 8,000 years ago, each successive warming peak is lower than the previous one, that is a clear cooling trend.

Rory Forbes
Reply to  Sunsettommy
March 31, 2021 2:34 pm

That has been my rebuttal of choice to any AGW true believer who gets all panicky about “climate crisis”. Geologically speaking, this plant is approaching the end of an interglacial warm period. If there is any crisis, it’s the continuation of the present ice age.

commieBob
March 31, 2021 5:11 am

The only way the alarmists can paint human emissions of CO2 as a problem is if its residence time is basically forever.

Even the alarmists admit that methane decomposes in the atmosphere in about eight years.

Methane’s concentration in the atmosphere is measured in parts per billion. That’s a thousand times less than parts per million. So, even if methane is 28 times more potent as a greenhouse gas than CO2, it isn’t likely to become a problem.

I did a quick calculation the other day. Even if you agree with the alarmists about the basic physics, the evidence is that thee greenhouse effect is over stated. Of course, CAGW is a religion so science doesn’t actually matter any more.

Pat Frank
Reply to  commieBob
March 31, 2021 7:15 am

CAGW is not a religion among the seriously political. cBob. CAGW is a tool. “The issue is not the issue,” remember? The issue is always power.

We’ve seen one issue manufactured after another. AGW, white supremacy, racist police murders, covid-19 alarm. All false and all involve screaming protests. They’re all founded on intentionally faked data. And they all have one outcome — more power to the government and more government in the hands of progressives.

That’s the issue. And the ultimate issue is lowering the boom of a police-state.

pHil R
Reply to  Pat Frank
March 31, 2021 9:18 am

Pat Frank,

This comment may be a little off-topic for the post, but not off-topic for your “The issue is not the issue.

I live in SE Virginia. As far as racist police murders, there was a mass shooting in Virginia Beach over the weekend. One suspect apparently pulled or pointed a gun at an officer and was quickly and efficiently “dispatched.”

Needless to say, local media and activists jumped to conclusions and claimed the “victim” was murdered by a white police officer and a gun was only “in the vicinity.” Turns out the “victim” was shot by a black officer and a gun was found at his feet. After that, crickets…the story didn’t fit the narrative they were trying to push.

Clyde Spencer
Reply to  commieBob
March 31, 2021 8:46 am

Well, after all, mathematics is racist and then by implication, so is science. If the ‘progressives’ get their way, we will revert to a world without math and science. Perhaps we could make a movie about it while we still can. Maybe an aging Mel Gibson could be persuaded to play a leading role. The plot might revolve around how to prove a person is a witch racist.

Steve Z
Reply to  commieBob
March 31, 2021 11:38 am

Current levels of methane in the atmosphere are stable at about 1.8 ppm, so if its capacity to absorb IR radiation is 28 times higher than CO2, the methane content of the atmosphere would be equivalent to about 50 ppm of CO2, or about 1/8 of the current CO2 concentration.

Warming of the atmosphere by IR absorption of gases is dominated by water vapor, whose absorption coefficients AND concentrations are higher than those of CO2, and CO2 absorbs about 8 times as much IR radiation as the methane in the atmosphere, so that methane in the atmosphere has very little effect on the climate.

The low residence time of methane in the atmosphere may also be due to its low molecular weight (16) as compared to 28 for nitrogen, 32 for oxygen, and 44 for CO2. In the gas phase at a given temperature, the average molecular speed is inversely proportional to the square root of molecular weight, meaning that methane molecules move about 66% faster than CO2 molecules at the same temperature.

Methane will tend to rise in the atmosphere by buoyancy relative to the dominant nitrogen, while CO2 tends to sink toward the ground, being heavier (slower molecules) than the surrounding air. When the relatively fast-moving methane molecules reach the upper atmosphere, some of them escape Earth’s gravity into space, possibly enough to balance out the low emission rates of methane into the atmosphere.

Although water vapor also has a low molecular weight (18), it tends to condense into clouds and rain back out at the lower temperatures at altitude. Methane has an atmospheric boiling point of about -161.5 C (-258.7 F), and the entire atmosphere is much warmer than this, so that methane will remain in the gas phase everywhere in the atmosphere, and can eventually escape into space.

Gary Pearse
Reply to  Steve Z
March 31, 2021 4:29 pm

Brownian movement overwhelms this gravitational “sorting”. The various gases are well mixed.

commieBob
Reply to  Gary Pearse
March 31, 2021 8:01 pm

As far as I can tell, that’s mostly true. The lightest gases do float to the top of the atmosphere and escape more than the heavier ones however. link

Antonym
March 31, 2021 5:29 am

The current study exemplifies the complex feedbacks and time scales that induce climate changes in the marine environment and is therefore well suited to estimate the expected consequences of today’s more rapid global warming – especially on the Arctic gas hydrate deposits.

A self-contradictory conclusion.

rbabcock
March 31, 2021 6:14 am

I would assume as the ocean parameters around methane hydrates change, they form in some places and dissolve or whatever they do in others. It isn’t a one way street.

March 31, 2021 6:46 am

Warmists do what Warmists do – they melt things…..they melt the Artic and Antarctic…they melt glaciers….they melt tundra….so they will melt the methane.

ResourceGuy
March 31, 2021 7:31 am

This press release is certified under the terms of the international Science as Religion Compliance Act. May the grantees multiply and inherit the earth–at your expense.

Olen
March 31, 2021 7:36 am

Good research. They did not tie climate change to man made and only mentioned it as a fact that the earth has warmed since the last ice age ended. Until they mentioned today’s more rapid global warming. A tag on the last sentence.

You know that feeling you get when you have to say something you don’t want to say. Only guessing.

Jackie Pratt
March 31, 2021 7:40 am

All that the article seems to get on about is qualitative gibber-goo. But as CB noted, it will be used (wrongly) as a tool by the alarmists.

Joel O’Bryan
March 31, 2021 8:07 am

I thought the Black Sea filled about 8000 years ago in a great deluge What am I missing?
Black Sea was large lake before the Aegean Sea broke though to flood it a hundred meters higher with salt water.
https://insh.world/geo/great-flooding-black-sea/

Vuk
Reply to  Joel O’Bryan
March 31, 2021 9:57 am

Barabulka with grappa.

Pat from Kerbob
March 31, 2021 8:17 am

Except there is no rapid warming now, and it was much warmer in recent times, so there is no issue thankfully.
If this stuff was to melt and release the methane uncontrolled, it would eliminate a massive future fuel source we will have when we control the release.
Win win

Walter Sobchak
March 31, 2021 11:21 am

The so called Black Sea is not really a sea it is a large lake. It can’t tell you very much about what is happening in the true oceans.

ATheoK
March 31, 2021 11:54 am

Previously, this baseline was determined using seismic methods, from which the so-called “bottom simulating reflector” (BSR) was obtained as an indicator of this base. “However, our work has now proven for the first time that the approach using the BSR does not work for the Black Sea”, explains Dr. Michael Riedel from GEOMAR, lead author of the study. “From our point of view, the gas-hydrate stability boundary has already approached the warmer conditions in the subsurface, but the free methane gas, which is always found at this lower edge, has not yet managed to rise with it”

  • BSR, i.e., “bottom simulating reflector”.
  • “However, our work has now proven for the first time that the approach using the BSR does not work”.
  • “From our point of view, the gas-hydrate stability boundary has already approached the warmer conditions in the subsurface”

A “bottom” simulator – reflector? That doesn’t work?
Yet, their “From our point of view”, that is, their opinions…

“In summary, we have found a very dynamic situation in this region”

A dynamic situation? as in Merriam-Webster’s defintion?

dynamic adjective

dy·​nam·​ic | \ dī-ˈna-mik  \

Definition of dynamic (Entry 1 of 2)

1amarked by usually continuous and productive activity or change

dynamic city

1bENERGETICFORCEFUL

Once again, they use words that do not mean what they want them to mean…

Then there is this:

The combination of these three factors – salinity, pressure and temperature – had drastic effects on the methane hydrates, which decompose as a result of these effects.

The current study exemplifies the complex feedbacks and time scales that induce climate changes in the marine environment and is therefore well suited to estimate the expected consequences of today’s more rapid global warming – especially on the Arctic gas hydrate deposits.”

“Drastic effects on methane hydrates”… There it is, inevitable doom, not from Mediterranean or Black Sea methane hydrates, but especially Arctic methane hydrates.

mkelly
March 31, 2021 2:46 pm

Years ago methane hydrates were blamed for a sharp warm up. There is a depression in the Voring Pleateau off Norway. It was though that the depression was caused by a sudden release of CH4 and causing a sudden rise in temperature.

Methane Hydrates could supply thousands of years worth of energy.

http://www-odp.tamu.edu/publications/104_SR/VOLUME/CHAPTERS/sr104_50.pdf

niceguy
March 31, 2021 3:02 pm

So there is still a chance for Nessie?

Gary Pearse
March 31, 2021 5:54 pm

Solubility of methane in water is about half that of oxygen 0.07g/kg at 10°C and increases with pressure. At the the sea bottom under high pressure, the very gradual change physicochemically that causes dissociation of the hydrate under a hypothetical warming scenario, would result in most if not all the methane going into solution.

Did the good Doctors note any gas bubbles rising from this body so near to the dissociation point? No mention of it. Even then, did the bubbles reach the surface? When you contemplate a research project, there is so much that you should already know

How about an obvious alternative conclusion that fits the facts: methane is abundant in the oceans which are teeming with life. During a glacial maximum, the hydrate begins to come out of solution, crystallizing at depths and temperatures in the solid hydrate stability zones, waiting there until the waning next interglacial to dissolve back into the seawater.

Tim
Reply to  Gary Pearse
March 31, 2021 6:29 pm

How much methane is released when glaciation causes sea level to drop ~400 feet?

Ewin
April 1, 2021 4:43 am

Methane hydrates are organic and natural. Progressives should love them.

Ewin
April 1, 2021 4:45 am

From a recent article here on WattsUpWithDat.

D146080E-D794-4508-B278-C3C4C71F4494.jpeg
ren
April 1, 2021 9:09 am

Radiation from the sun is the primary source of energy for the Earth’s climate system. Changes in the Earth’s orbit around the sun cause variations in the seasonal distribution and amount of solar radiation reaching the earth. Records of past climate show that there is a correlation between these variations and long‐term climate changes [Hays et al., 1976Imbrie et al., 1992]. Interglacial conditions begin with increasing mid‐latitude summer insolation and end as mid‐latitude summer insolation decreases. Orbital‐scale climate cycles are driven largely by variations in solar radiation associated with precession, obliquity and eccentricity of the Earth’s orbit. Recent studies of the Asian monsoon show that the transitions between the glacial and interglacial conditions took place abruptly, perhaps only in century‐long events [Wang et al., 2001Yuan et al., 2004]. However, it generally takes about 10 ka for the insolation to change from a minimum to maximum and vice versa.
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2005GL025401

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