Methane Hydrates: Natural Hazard or Natural Resource? - Perspectives on Ocean Science

Methane Hydrates: Natural Hazard or Natural Resource? – Perspectives on Ocean Science



good evening and welcome I am Nigella Hill Garth and I'm the executive director of the Birch Aquarium at Scripps Institution of Oceanography UC San Diego and it's a great pleasure to see you all here tonight seem so many friends of Scripps Institution of Oceanography and the aquarium and it's my great pleasure this evening to introduce our speaker dr. Miriam Casner dr. Kestner was born in Czechoslovakia and received both her bachelor's and her master's degrees in geology from Hebrew University in Jerusalem Israel and she then received her doctorate in geosciences from Harvard and she has received so many awards and honors and served on so many national international advisory committees and held a variety of academic in ministry positions that if I began to read even a few of them we'd be here a long time so I just in summary she has a very distinguished scientific career and a very distinguished administrative career I'm just going to read you a very few of her honours and they include a fellow of the Geological Society of America the hands Peterson medal the sweet the Royal Swedish Academy of Sciences a fellow American Association for the Advancement of science and a Guggenheim Fellow she came to Scripps in 1972 and she conducts a variety of lab research as a full professor here at Scripps and she investigates such diverse subjects as a Geo chemical history of seawater submarine mineralization processes the mineralogy and geochemistry of marine sediments and the nature origin and fluxes of fluids in subduction zones and she's published over 135 papers in refereed journals and she also teaches many classes here at the University and she's participated in I think at least 20 ocean expeditions and was chief scientist on several of them and I was talking to one of our professors here at Scripps the earlier this evening who has been privileged enough to be on several of those ocean expeditions with dr. Costner and says that she has more energy and works harder than anyone else he's ever been to sea with in his life and he's been a lot of trips that she is just a phenomenal scientist at sea and really puts it the rest of us to shame so please join me tonight in welcoming dr. Miriam Kastner for her talk entitled methane hydrates natural hazards or natural resource Thank you Thank You Nigella how can you hear me okay thank you for the nice introduction very generous introduction and I will go immediately into the talk because I'm trying to cover a lot of things tonight with you as you see these topical there is not exactly what I'm going to do I'm going to talk about this general outline we're talking generally about methane hydrate or gas hydrates it's a class rate type structure when you don't know about a class weight type structure it's a structure that has a host and then it has guests it's like in a hotel the people are coming and going so the structure of hydrate is basically water ice and different gases come in and out in the hydrocarbon gases as a host gases so I'm going to talk a lot with what what the hydrates are and why do we care about them how important they are the occurrence in nature whether they occur is highly susceptible to climate change you will see why we worry about it in visual respect to climate change and easing any evidence in the past the hydrates we're really susceptible to climate change and what about resources is a new source of energy everybody is talking about resources I'm going to talk very little about it I'm going to emphasize my talk about the climate change and about a Geo hazards these are the two topics I'm going to put a particularly mention tonight let's first look at the guys hydrates I already told you what it is here you see the structure and these red ones and the white these are waters and that is the gas in this case it's a methane but it could be a same propane or co2 as well and the real amazing thing about this hydrate structure is a really amazing thing about the structure is the a the storage capacity if you take one centimeter cube off you want to talk about you know inches whatever you want to talk one cubic inch and you decomposed it it looks like ice and you decompose it the amount of gas in such one centimeter cube is 160 270 times the volume of the hydrate so it stores a lot of gas in a small oval area and it also is stable at low temperature and pressure I think I will stay here because I have to move the computer okay here you see hydrates that's how they look like they look like ice that's water but the difference between ice and that is if you take a match it burns it here you see the fire and that's methane it's beautiful fire very pure and it forms co2 so that is in terms of future of energy that is what we will talk about here you see an example recently many countries got very interested in it and that happened in Korea they found these guys hydrates and on the ship they got so excited somebody just took a match and it just looked at it how it burns because it's the first thing you do when you find hydrates actually okay ah hey what here to try it out when I teach the class I do the same thing in the class you know we just shows him how it burns in terms of structure this more than one structure these are the two main structures and the difference is that the cages the size of the cages and the size of the cages determines what kind of gases can enter into this hydrates structure one is particularly the methane hydrate in the co2 hydrate this structure here is a structure to which can accommodate his larger cages also can accommodate the higher hydrocarbons when we have in oil terrains for example the Gulf of Mexico there's a lot of structure to the existed type of structure age even larger cages so all kinds of gases can form hydrates and today I'm going to talk mostly about the structure one and methane hydrates particularly now in terms of stability they are stable I told you it at low temperatures and high pressures so here we have a stability diagram what we call the pressure is now depicted here in terms of depth because we're talking where does it occur in nature so let's just look at depth in meters and that is our temperature here as you see that is the freezing temperature zero so the first thing you see is which is actually stable at higher temperatures than zero and then I think about it up to 30 degrees centigrade which is pretty warm but let's take the bottom of the ocean today's one of the ocean most places is about two degrees centigrade let's move up here and then go to the left that's a logarithmic scale so what it tells us that the temperature of the bottom of the ocean at about two degrees centigrade we can get hydrates at about 500 meters of water so it's not very deep it's very quite shallow in margins 500 meters of water where the hydrate is already stable so we do have the right temperature we do have the pressure because it's the water column what we need is a methane so we need three things we need the pressure temperature and the methane when we look at the permafrost areas here we see again now we have the water and the sediments mist is the same as in the previous diagram but when we have the permafrost and we have colder temperatures there's and we have in it most of the ocean then the hydrogens can form all it about already at about hundred meters of water 250 meters of water so that it can form much siloam and that is the temperature again the methane is needed and that explains this diagram when we look for methane hydrates do occur on earth you see it is in continental margins it's not in the middle of the oceans and continental margins in the promo first area Siberia here and in in the Akhtar Arctic it makes a lot of sense because that's where most of the organic matter in the ocean is most of the organic carbon in the ocean ninety percent of it is in continental margins that also is very nice because we don't have to go very far from the continent in case it is really an energy source we don't have to go too far into the deep ocean so that's where the methane hydrates are on earth now how much of it is happening why do we care about it because there's so much of it here in 1988 when baldon who is a famous researcher research on gas hydrates came up with this type of diagram he made the calculation based on the organic matter and the methane production and these units are in 10 to the 15 tonnes gigatonnes if there doesn't mean much to you it you know what it trillion is trillion is a big number we talk about a thousand trillions okay so it's ten thousand thousand trillion you know a trillion of of tons of gas hydrates now if we look at the area we know how much fossil fuel we have on earth and here we have the cold just a fossil fuel if you take all the fossil fuel on earth there is more carbon in the guards hydrates then in the fossil fuel so we are talking about something enormous now recently scientists have recalculated all kinds modelers you know they changed and calculate and do some new calculations and they come up with different numbers came up with low is lower numbers but even if it is you know an order of magnitude less it still is enormous ok the question is how is it distributed and why do we care I mean it's there so maybe it's there why do we care about it in the United States we already knows that we have in the United Stated but here we have cubic feet of gas and most of the things we know now is it Blake rich on the East Coast no Slope of Alaska Gulf of Mexico and again in Alaska these are known deposits of hydrates in the United States margins and certainly this is much more than California marching they also Northern California margin we have Oregon Washington there's mozzies there are hydrates all right so all these hydrates exist I mean with a 16 times more things times list it's a lot they're so white how is it related to global change first of all let's look at the origin of the methane we need the methane in order to get the hydrates so the origin of the methane is either biogenic or thermogenic thermogenic means the organic matter is being decomposed is being decomposed by biological bacteria or it's being heated up in forming methane so these are two origins of methane and they have the on geochemical signatures we can distinguish with them very easily we analyzed them because they have carbon isotopes which are very different so Ganic meter the starting organic matter has carbon isotopes of – 22 – 27 so it's very different from that now the other thing which has happened the carbon 14 of these hydrates is usually already is used the qaol methane hydrate company depleted its already dead because most of the carbons the organic matter which is used in this hydrate is old and the carbon-14 has a half-life of 5730 years so after about thirty five forty thousand years it's very difficult to measure 2014 so it is also not live if new organic matter is a new organic matter has a lot of carbon-14 so it has its own geochemical signatures which is very important and this very negative carbon isotopes was used by geologists to trace past events because how do you know methane once it's not preserved you don't know what the methane was the but if we look at a geological event we look at the carbonates which inherits some of these carbon isotopes and geologists have looked at changes in carbon isotopes to see if indeed in the past the hydrosphere related to climate events now here is one example which is the most famous example and that is 55 million years ago it's a boundary between Paleocene and Eocene I just want to show you here is an example of desert temperature and that is a carbon isotopes I showed you here you see behave the deep sea and we have the surface ocean you see what happened at that time it was a 1time on earth and both at the surface of the ocean and the deep ocean the temperature were very warm here we have the deep ocean was as hot at 16 17 degrees centigrade and I told you today it's 2 degrees centigrade so the ocean was much much warmer than today and what do we see the carbon isotopes we see that at the time that the ocean warmed up so much the carbon isotope became lighter and the geologist and geochemist emotional buffers we're wondering you know what caused this lightening of the carbon isotopes and they suggested that this dissociation it was a lot of gas hydrate because the ocean warmed many of them you saw the stability diagram did not survive they dissociate it and just release the carbon which is very light and they caused this now there's a lot of controversy about it in the literature it was a very exciting time with this paper by Jerry Dickens came out but today's a lot of controversies because there different ways that carbon isotopes can be can become lower can become more negative so it's not really absolutely clear that that was the case the reason that they came up with his ideas about because both the surface ocean and the deep oceans they became more negative so it means it was a big event the whole ocean changed its carbon isotopes which is not so simple to do but it is controversial it's not clear that that indeed was the case but that is a type of things that geochemist are looking for to see the effect of climate change on on gas hydrates and what remains how do we read how to interpret it another time the people interpret God's hydro dissociation because of warming was in the snowball earth they also was warming there and and they see the low carbon isotopes so there are these events the people are looking at and trying to interpret but we should realize it's the interpretation we really don't have the methane to analyze okay let's look a little bit about the modes of occurrence of hydrates today so let's look at the present system and let's try to see how what what can we figure out what can be predict based on our prison system in knowing the physical chemistry of the gas hydrates now the are mostly marine or in permafrost if we take the amount of gas hided in the marine environment per first most of it isn't the marine environment and that is five percent but even five percent of a huge amount is a lot now in the oceans are two types of appearances of hydrates some of them about 20 percent 15-20 percent of the hydrates are at the sea surface at the very sea surface close to the surface and the rest of it are deep down at the base of the Gods Hydra disabilities on the depths of the base of the stability zone depends on the geothermal gradient what the temperature is mostly it's been about 200 meters 300 meters burial not more than that there's one place on earth it's at 600 meters but usually it's not very deep okay in terms of depths of penetration in the ocean it's just that depth what I'm going to show you I'm going to carry you through now some pictures showing user appearance because it's really if you haven't seen it it's amazing to see and I will show you first the surface the seafloor appearances here behind the Gulf of Mexico you see the seafloor currencies you see the methane is bubbling out here and when everything is all these nutrients coming up there's a lot of life associated with it like when you have hydrothermal systems there's a lot of life associated so these are benthic communities and they are based on chemistry and not photosynthesis and I'll show you another picture of the same thing you see that's oil here and they sent in a some muscles here so that a lot of there's a lot of life associated to be this venting and the seafloor gas hydrates that is a yellowish one because oil is associated with it so we drilled a core here from a submersible and that is yellowish because some oil is associated with it that's another very famous sea surface type of a hydrate and that is at Berkeley Canyon in British Columbia and that was ever discovered by fishermen what the fishermen did they trout fishermen today trowel a lot and they picked up a ton of something they didn't know what it is they saw something white and they brought it up and they saw the ocean bubbling churning they were they didn't know they were smoking luckily nothing happened in our on the ship and one of them tried to be very helpful to scientist it took a piece and put it in the freezer in the refrigerator in the kitchen luckily it wasn't a big piece so the refrigerator did not explode from all this gas that was very lovely but it came back after about an hour and couldn't see anything it was all gone it just did not stable at surface temperature and pressure so that is or occurrence of Bartlett Canyon and I'm going to show you what happens you see it needs methane so in when you see something at the surface that means that the methane is coming all the way to the surface the moment you take it away from the sea floor see what is happening to this hydrate it is decomposing you will see now that is in berkeley canyon that is a submersible in our a robot which is picking up a piece the hydrate is less dense than seawater so it's floating if you take it away from the seafloor so you can imagine if suddenly there will be a decomposition of a lot of hydrate what can happen in the oceanic environment here you see floating pieces there because there are less dense than seawater and you see start seeing some bubbling because it was taken away from the sediment it starts bubbling and now they're sort of analyzing it by a laser but very soon you will see the fate of these hydrates if they indeed get released from the seafloor or from the slope and start floating in the ocean so here you see a piece holding this muscle is holding it and watching it and you see very slowly it starts to bubble because it was protected by some oil you see the yellowish part is protected by oil but you see the bubbling is increasing with time and very soon you will see some of your system some oil here and very soon you will see how quickly it bubbles and eventually it's going to decompose completely there was a suggestion that the Bermuda Triangle was formed by this height weight in the past so now you see what's happening here and that is what is happening is you can measure what this fisherman saw when this piece came up you know that is a kind of thing that the fisherman actually saw and eventually in a very short time it just disappears and the methane will be oxidized by oxygen to co2 some of it may go to the atmosphere and cause some global warming so here we are worried that one of the problem is if some of the methane hydrate succeed to go decompose and the methane succeeds to go to the atmosphere then methane is very potent greenhouse gas and will cause some warming the way we study the surface hydrate is by using submersibles or our V that's one of my students sitting in the submersibles they are all waiting in line to go down to the bottom of the ocean you have to realize then we find these guys hydrates we can't just bring it up possible because it's going to decompose on the way you saw what's happening to it correct it will decompose so we need some special containers which are insulated and pressurized in order to bring these hydrates up to the lab and study these hydrates okay now so these are the sufficient hydrates the other hydrates in the ocean it's a bottom of the stability zone that is the deepest one in the Andaman Sea and that is the base of the stability zone you see here a reflector quick you see here we have red above black and here we have black above red but that indicates here we go from water to sediment if we go to the less dense material to the more dense material here we go from the hydrates to gas down here is gas so this is the inverse reflector and that's how do you physicists recognize this kind of boundaries using this inverse reflection and the hydrat mostly occurs here and becomes less and less towards the top because the methane is addicting from below so that is an occurrence but sometimes you know to do that you need to drill ship because you have to go deep but it's not always nice to be on the door you see if you have this kind of an ocean so we all don't always have a very pleasant situation at the ocean here you see a type of an ocean which doesn't allow you to do very much work so once in a while you experience that as well okay when the course come up what do we do with the course but we are getting hundreds of meters of course so we cannot analyze the whole thing they are using infrared and wherever the cores are cold that's where the hydrates are so we are not going to waste very much time on that here they're going to zero in on this places which the hydrate is because we want to pick it before it B composes so the infrared is very very helpful for us to zero in and sample it and here you see the Andaman scene we analyzed the pore waters for the chloride because when they decompose the seawater becomes diluted the poor waters become diluted but you can see that the distribution is from the bottom up and we have much less here it's a different types of distribution you see here also the sediments are not always complete everywhere the hydrate is it chooses its sediment when the sediments are coarse or fine the hydrates like to be in coarse sediments in this case these are ash layers because it isn't in a volcanic arc so that it makes sense because ash layers have more porosity and permeability or sand stones so when the hydrates have a choice of sediments they go into the course of sediments which is a very important thing for for exploration to know that okay so you're looking to the coarse sediments they go to the lab or toys and we take the poor water we squeeze it here and we analyze the pore water by this squeezers okay now you see here we see some coarse that immense conglomerate in the permafrost is totally cemented by hydrate and here we see a sense stone which is totally cemented by hydrates but most of the sediments in the oceans are not coarse-grained and therefore the question is whether they hydrate or cure so here you see some nice appearances of hydrate in the final grain sediments what the highroad is doing it needs to grow because it's forming so it's pushing away some of the sediments aside and it's just forming this kind of concentrations in the final grain sediments because it cannot just penetrate in between the fine grain so it finds its own place because it has to form there it is in the stability field so that's how we find it and here is one case we are not in the ocean behind Lake Baikal you also see it picked up certain sediments where it's forming in led by Carl so it doesn't have to be in the ocean but that certainly quantitatively is not very important so we have seen how it forms and now the questions are we know where the former is okay what is a global integrated flux of methane from permafrost and Marine base hydrates because global warming is here I suppose it most of you in the audience here do agree with this statement and is something already happening are they already decomposing to a certain amount in the permafrost and maybe in the surface layers of the ocean where the heating the warm warming up is occurring first is it happening or not we don't know or do we know ok and then the other question is what is the potential the contribution of methane hydrate for future climate change if it's not happening yet what can we expect in the future are they going to play a role in global climate change as a positive feedback because if they do decompose and they succeed to go to the atmosphere methane is exceeding to go to the atmosphere then methane is a very potent greenhouse gases I already mentioned to you before so these are the question that we are asking and and then the question is about our gas hydrates related to Geo hazards in landslides as well because they cement the sediment so if they decompose and this cement disappears can they cause some landslides so these are type of questions we have to address and in the question is how to address this kind of questions before they're just very quickly why is methane so important for us because it is a greenhouse gas it's a radiative impact of methane is it about twenty six times that of co2 okay so that's why methane is more potent I mean is more potent than co2 now in the atmosphere today the methane doesn't last very long it gets oxidized by the radical OAH but if there is more methane in the atmosphere today's a half-life of methane in the atmosphere is nine years but if there is more methane in the atmosphere then they half-life increases as well do we have some times in the past that there was more methane or less making the methane fluctuated really in the atmosphere and then if we do look at these times then can we understand the cause of this increase of methane and maybe understand the role of gas hydrates in this fluctuation of missing I'm sure you've seen this diagram several times in the series of lectures that is a Vostok ice course here is today and 400,000 years ago these are four cycles of glacial interglacial integrational and glacials we are here today and what we see here we have a hydrogen isotopes which are proxies for temperature that is the co2 and that is a methane so we definitely do see that the methane and co2 behave similarly and it's very I mean today the argument is no more is a methane really the trigger of the warming or is a feedback it's clearly that the methane is not a trigger but is the feedback but once methane is coming up then the warming can keep becoming warmer and warmer what is happening today here from the IPCC report they are getting here six cycles of of a glacial interglacial and here we have from 2002 one to just eight thousand years and you can see that suddenly the methane increases tremendously here and here it's expanded it's 2002 to 1986 the methane keeps going up these are different measurements for different sources but they all show some increases of methane so the question is what is causing the increase of methane in the atmosphere today it still keeps going now the possible causes of abrupt increases of atmospheric methane and here are three possible causes the wetlands definitely are producing a lot of methane in that is this you to be the most important source of methane to the atmosphere rapidly because once the climate warms they expand as well and recently that has been added to the list of possibilities in the Siberia in Alaska there are these thermal crust lakes and they produce quite a lot of methane and the question is about that one everybody is talking about these two but it's very little discussion about that one because it is a more difficult thing to measure and to observe so the question is is something happening there as well because there definitely is a possibility going there's a lot of hydrate one of the students of gesturing house gave me this slide it's just a nice slide of wetlands I thought you'd like to see that okay let me take the IPCC report what we see here we see that the sources of methane to the atmosphere today are mostly on top or genic and from the natural resources it's mostly wetlands as you can see they don't turn in this report hydrates in the ocean as a source is not considered as an important these numbers are not very good these numbers are not very well known they just report what is known today so the question is do we want to know more about it and see if that's correct or not because definitely once you have a total and you have sources that you don't take into account you have to rethink the rest of it okay so currently in the atmospheric car making budget also they're using the carbon 14 depleted where there's normal carbon 14 is a natural source they use that is how much oil on top o genic input is is it we are producing and it goes into the atmosphere on the other hand methane hydrate in other geologic sources which are not caused by anthropogenic processes are also carbon 14 dead so if are going to the atmosphere then this number here in the IPCC is also incorrect we have to adjust it okay so definitely knowing what is happening in the ocean in permafrost is very important in order to to have better numbers for all these calculations and as well as modeling now how do we know the source of parallel methane usually we have carbonates and they have the isotopes of the methane but the best way to see Palio methane is to go to ice cores the ice cores they have the atmosphere and there the methane is and the methane can be measured correct but I suppose don't go that far geologically but we do the best we can so here is a theoretical way of looking at ice cores if we look theoretically carbon-14 is decaying so here we have carbon-14 active carbon-14 new carbon-14 it's decaying and eventually it is I mean it's depleted eventually so that is a theoretical curve with time before present uses are known numbers here it's just a theoretical curve now in the ice cores we do see that at fourteen point seven there was a warm warming events a building and there it is the Younger Dryas now theoretically if the warming was caused by some introduction of methane hydrate and that is a question do we see in the ice cores introduction of methane hydrate this carbon-14 is already depleted so it will lower the curve so the curve will not look like the red one but we look like the yellow one one of gesturing how students Botanic Paterno who did finish his thesis just a few weeks ago did a marvelous job he did a beautiful piece of work he analyzed the methane in this gas high in in these ice cores that is a very difficult task and he came to the conclusion that indeed by by modeling a few percentages of the carbon-14 in the ice cores at these events came from gas hydrates so that is one step forward which is very important not much less than ten percent just a few percent but at least he suggests based on his interpretation of the data that some gas hydrate contributed to the carbon-14 at these times in the ice cores all right so what fraction of the National methane production reaches the atmosphere how do we find out the main methods things are the following when methane is being formed either biogenic Lee or thermogenic Lee what is happening in the sediments before it goes anywhere the bacteria are utilizing a lot of the methane by anaerobic oxidation so that is happening all over the place in the sediments and then some of it when your eyes stability field of – hydrate is sequestered in gas hydrate and that is a lot of methane when it comes to the seafloor you saw the benthic biomass is using some of the methane and what succeeds to coming to the water column in the water column there are other bacteria they oxidize the aerobically the methane in the water column and as you know the ocean is quite deep at most places and as they dissolve the utilize oxygen and produce co2 so the question is after all these things how much is left to go to the atmosphere what is very clear that climate change may already if not it most likely will impact the sink of the sequestration of gas hydrate because if the ocean is warmer the depth range that gas hydrates can occur will decrease it also will affect the this number for first of all if the ocean is warm as there is less dissolved oxygen in the ocean so it will affect at least these two sinks of the hydrate so most likely more and we succeed to go to the atmosphere but how do we measure it how do we do an experiment how can we go about in a good numbers I mean we can see Witek lycée all that is going to happen but how can we give numbers so we did an experiment and we did is in the back of Mexico what you see here in the Gulf of Mexico when you dive you see a lot of sheeps a lot of plumes that is a sonar of plumes goes on some of them go all the way to the seafloor it is seafloor some of them have oil they have some slicks of oil at the sea floor and when you use satellites NASA has satellites you can use and you can count count in the Gulf of Mexico how many of these slicks do exist and then maybe we can do some calculations if it can determine how much methane is escaping to the atmosphere because if this plume goes all the way to the surface of the ocean much of it will go to the atmosphere the question is how many of them do we have how much is coming to the atmosphere today how do we do it okay how do we measure all that so we design an experiment and a student of mine who is now a post-doctorate is here and the audience's welleven Salamone was responsible to much of the work that we did so what we did we used a submersible here isn't a submersible I did some diving you see you have to go from the top in you can't just enter you don't have a door here you have to climb up there so what we did is a following we went to an area in the Gulf of Mexico where a lot of these plumes a lot of bubbling you go down there and you see all these bubble plumes and so we took an area which was known to bubble with all these biosynthetic communities but on the sea floor and we took this submersible because this submersible has the capability of sampling water from inside I can from inside sample the outside water so what we did we took say submersible and went all the way to the bottom and in this bubbling plume we were in these bubbles we slowly slowly moved up and kept sampling the water to see eventually the concentrations of the methane all the way to the surface so we got the concentration of the methane at the ocean-atmosphere interface as well so in addition we took some city decent casts that we analyzed the methane in the vicinity of these plumes as well so we have the original distribution of methane in this area we also put some new instruments on the seafloor and we measured for a whole year how much methane is coming from the sea floor into the ocean and we analyzed the sediments and based on the profiles we got numbers how much of the methane is being oxidized in the sediments so we had all the different parts of the puzzle in this region are sediments and a and B came up with some numbers it's just one region that we did this experiment you can imagine you can't email it worldwide and what we came up became that in this region there was one Tara gram of methane which was escaping to the atmosphere which is 25 percent of what the IPCC gives us and it's just one region okay is it a 25% of the given ours there must be much much more in the word ocean then we take the seeps in different areas of the ocean where some numbers unknown B come up with 542 10 teragrams which is 2 times what IPCC is giving as a natural source of methane now when we take all the other geological sources there coming up is about 30 telegrams so we're starting to get some numbers and the numbers are much larger than they actually have in the literature and in the IPCC report okay in the permafrost region we also think that some methane hydrate apparently are already dissociating and the reason that we're thinking that is happen there is a following when the sea level is low and these are methane hydrate the atmosphere is very cold in the permafrost the ocean is warmer than the atmosphere if the ocean starts getting on top of the hydrate then suddenly there is a thermal shock that the hydrates are getting because the ocean is at least 1015 degrees warmer than the atmosphere and this warm pulse is going slowly into the hydrate and eventually a hydrate have to dissociate so sea level change in the permafrost is the thermal pulse that causes dissociation of the hydrate so what we saw up till now is that some methane is escaping to the atmosphere we cannot say whether it's hydrate or not it could be just gas methane gas but definitely methane is escaping today from the air from the ocean to the atmosphere more than the IPCC is giving to us and there will be more later on if the ocean become warmer and the permafrost is also impacted or will be impacted further in the future when the sea level will keep on rising and the thermal pulse will reach the permafrost the only things that I didn't show you now very briefly is what would be the impact of this deep hydrates on lens slides and I would just very quickly go through that and I will show you that see for stability is another concern now before I show you a few slides on that one you should realize one thing that methane is as we say the very important gas now it would be great to capture the methane hydrates for energy before it decomposes that would be the best thing to do if we don't capture it and we let it to decompose the first are going to lose some methane that we are not using and we are going to get some negative impacts on nature so it would be nice to do a lot of research and try to see if indeed the methane hydrates are in new energy source or not I mean there's a lot there but the question is how does it occur before they get decomposed so that is one thing they we need some funds to do that now in terms of Safra stability I told you already that they cement the sediments as you saw and the question is if methane high if by dissociation the seafloor stability can be impacted and as you can see that there are so many processes that can trigger failure of the slope earthquakes when there is a steep slope and is web with the position sea level fluctuations but also when Hydra dissociate there's so much gas formed there locally that is overpressure and it causes some seafloor failure so making hybrids could cause seafloor failure so how do we go about studying that but it's happening there are some many scars of many many landslides huge landslides after the glacial maximum the most famous one is in no way the story goes and that was suggested to be caused by methane hydrate dissociation 80 200 years ago when some warm water came and impacted the slope of Norway and there was a big landslide recent work by scientists when they again dispute this interpretation so many of the existing big landslides scars these are scars after you come at least light happen you have a scar so you have to study the scars it's very difficult to study scar and reconstruct what really happened so the best thing is to go to certain areas which have a potential of sliding and study them and see the different properties before they slide and learn about potential c4 slides in relation to missing so here we and the way to do it is to do some mapping do some geochemistry to see if methane is really associated in this region and then eventually monitor these sites now we had a collaborative study with Woods Hole it's Scripps Neal Driscoll and I were involved in this study and what the Woods Hole and Neal Driscoll found along the shores of Virginia in North Carolina they found a large scale of Ln elongated some things they called glass blowouts what are this glass blowouts first of all I will show you where the area is we are here in North Carolina and Virginia and we are talking about this region here we are talking about this region here there is a sequence of blowouts which they interpreted to be related with methane but it didn't have the evidence when you look at the blowout that's how they look like that is a sea shelf and you see this blowout uses dimension something is missing here definitely something blew out is a large scale you can see the scale here that is one of the blowouts here you see a second blowout and you can see it's already filling in so it happened some time ago that this blowout was filling in so what did we do yeah also there are some carbonates autogenic carbonates associated with these blowouts and they usually indicate methane but they didn't really measure the methane so what we did we went out and we did the following that is an AUV an autonomous vehicle here is a methane sensor and these autonomous vehicles are wonderful you play you are actually they have some very special computers and they're being sort of they're being told what to do at night they're being told where to go and what to measure and where to measure and this one was sent to move around in this blowout at 3 meters above the sea floor and measures them same distribution in this region to see if methane is really coming out we sent it at night and during the day what we did we did take some course and we took some cast in the water column as well in addition to that and these are all the course we took in the different blow outs and eventually we got some data and what you see here that is blow out be for example you can see that what this we found was that at a certain depth at about 110 meters there is an increase in methane in the water column near the edge of the shelf and then that happened in all the different blow outs so when we get an integrated map here we see what water depth from a hundred two hundred sixty meters the depths of this blowout is about 50 meters so what we see here we see the shallow part and here we see the deep parts of the blowout and it will take the methane concentration we see that the methane concentrations are confined to here and not in the deep parts of the blowouts and we also took some course and became up with the geochemistry that indeed methane is involved in these in this area so in summary I cannot show you many of these results because the time in summary that we found out that the active methane venting is concentrated along the upper parts of the blowout wars so first of all we identified the methane and also the location of the methane and the formation of these linear arrangements of pock marks or blowouts is likely related to trending tension due to downslope creep as a self brake so that is an area of potential landslide so what we need to do now is to monitor this region before there is a big landslide and just have this car to work with okay in big landslides you know can be very dangerous but for tsunamis and some other things as well so you saw the relationship between high and global change in slope stability so what should be doing the future really we have to identify natural gas hydro de posits where are the big deposits which are the most dangerous ones and are the best for energy and also analyze the mitigating hydrogen related geo hazards that is something that we have to really understand and predict and in analyze now to do all that we need to develop some new technologies for both and these things do cost money the fact is the u.s. is spending 10 times less money on this research and Japan for example or India so there are so many countries are interested in it worldwide and we are not spending enough here in the United States and we are hoping that in the future things will change and we'll have more because we are getting more evidence of the importance of these gas hydrates for our environment both energy and may be hazards thank you

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22 thoughts on “Methane Hydrates: Natural Hazard or Natural Resource? – Perspectives on Ocean Science

  1. Mam does methane hydrate cause pollution? I mean are they polluting? Plzz tell me an exact answer to this question

  2. Methane Hydrate is Stable in an environment of High pressure and Low temperature. Lower the pressure environment and the Methane Hydrate expands. Expansion moves the Methane Hydrate toward the Low Pressure Low Temperature Environment. As pressure is lowered as in a Blow Out Situation where Mud Weight is rapidly decreasing due to displacement by expanding Methane Hydrate Phasing into Liquid Methane Mud the Methane enters the Low Pressure Low Temperature Environment where Liquid Methane Mud is Stable. In a Blow Out Situation rapid velocity of Fluid causes Friction Heating and more Expansion due to Heat. As the Velocity and Heat of the Methane Mud increases the Methane enters the Low Pressure High Temperature Environment where Methane Gas is Stable. Shake a champagne bottle up and pop the cork. Now put the cork back in!

  3. Methane Hydrate is Stable in an environment of High pressure and Low temperature. Lower the pressure environment and the Methane Hydrate expands. Expansion moves the Methane Hydrate toward the Low Pressure Low Temperature Environment. As pressure is lowered as in a Blow Out Situation where Mud Weight is rapidly decreasing due to displacement by expanding Methane Hydrate Phasing into Liquid Methane Mud the Methane enters the Low Pressure Low Temperature Environment where Liquid Methane Mud is Stable. In a Blow Out Situation rapid velocity of Fluid causes Friction Heating and more Expansion due to Heat. As the Velocity and Heat of the Methane Mud increases the Methane enters the Low Pressure High Temperature Environment where Methane Gas is Stable.

  4. Methane Hydrate is Stable in an environment of High pressure and Low temperature. Lower the pressure environment and the Methane Hydrate expands. Expansion moves the Methane Hydrate toward the Low Pressure Low Temperature Environment. As pressure is lowered as in a Blow Out Situation where mud weight is rapidly decreasing due to displacement by expanding Methane Hydrate Phasing into Liquid Methane Mud the Methane enters the Low Pressure Low Temperature Environment where Liquid Methane Mud is Stable.

  5. Methane Hydrate is stable in an environment of High pressure and Low temperature. Lower the pressure environment and the Methane Hydrate expands. Expansion moves the Methane Hydrate toward the Low Pressure Low Temperature Environment.

  6. what are the odds that about a 100,000 years ago a methane bomb went off too? or maybe even 15,000 years ago at the end of the last ice age? with tectonic plate movements and constantly rising mountains it is quite feasible that methane 'bombs' are a trigger for climate change and of course global warming.

  7. At 10:38 Dr. Miriam Kastner makes a mistake that over-estimates the methyl hydrate estimates by a factor of 1,000,000. She is using the European "gigaton" (10**15) when the North American "gigaton" (10**9) is always used in these graphs and tables in my experience. 

  8. From the molecular graphic at 5:08 I calculate 60 cubic metres of methane at STP for 1 cubic metre of hydrate, not the 160 cubic metres. I'm going from memory about 1 mole occupying 22.4 litres STP. Perhaps I'm missing some aspect. Check it out yourself. 

  9. I can't wait for the world to end, so much iniquity going on, I don't want my kids to grow up in this sick and dirty world.

  10. please check out the date sadly whats being said now 2012 is really bad. Lets put it this way. Reminds me when my students and I saw the world trade center on fire and the teachers in the lunchroom saw them go down. I saw a fellow teacher in the hall and all i could do was say. This is real. Well this is real too. Much too real. Keep your ears open and use ur heads folks.

  11. We all need to be tracking this information. It appears much has been known for a long time.
    Get informed, spread the word and pray for peace and progress on this topic.

  12. @tranquilocito If you added up all the cow farts for the past 100 years i dont think it would ever even comes close to what a single valcano could vent off during eruption…. which they said was like 5 trillon,trillion tons…

  13. ahh! just a few more degrees and the master plan will be complete…
    Yeah, if that stuff decides to gasify which a warmer ocean will surely encourage, we're through and rather quickly too. Make the gas dense enough in the atmosphere and by golly no smoking everybody~!
    thanks for the video and it is a worry no doubt!

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