The tenth Mapping Ancient Africa seminar was delivered by Cecile Blanchet (Helmholtz-Zentrum Potsdam). The talk presented new research on climatic change in Africa during the Quaternary period.
To find out more about the Mapping Ancient Africa project visit:
The Mapping Ancient Africa project is a multi-year project funded by the International Union for Quaternary Research (INQUA; https://www.inqua.org) Palaeoclimate commission (PALCOM) and Humans & Biosphere commission (HABCOM).
Foreign welcome to the 10th seminar from the mapping ancient Africa seminar that we have we’re really really excited to have CCO today with us from the Chiefs that in pots of Germany she’s going to talk about ancient African rivers and what they can tell us about the future I’m
Really excited to have her here and I would basically just cut a throat and hand over the stage to you and I thank you yeah thanks uh to both organizers Stefani and William to to host me today and yeah I will just share my screen and start the presentation
Should be fine we just try it exactly so um so I’m presenting but of course this is uh this is work that has been done with many people um people from the gift said um in Pakistan University Leipzig and Tobias and Excel who are from the University of Hawaii and Busan
In Korea so um yeah and we will talk about uh engine reverse which means either they are extinct or extant but they indeed tell us something about what might happen in the future so the first thing is um why Rivers so I’ve been working on on
Rivers for for the past few years and basically they are very important components on Earth so here we see the the map of Rivers and the color coding shows how so perennial or not they are so the blue colors are for perennial rivers and um so non-preneurs with the flow intermittence um in reddish or orange colors and basically they are important for ecosystems both on land but also in the ocean because they transport
Nutrients and fresh water and they also open waterways so um they help for Mobility we know that because we drive very often along valleys so rivers are very important for that for our our and animal mobility and of course they play an important role in terms of landscape evolution in terms of erosion
And um yeah the scale of things and finally because there are a lot of human on earth we cannot um we cannot forget that they also play a very important role for people um subsistence and for their their living interestingly enough I’m working in a region where there aren’t much Rivers
Nowadays so basically it’s this great colors on the map so in North Africa um well so on the on the legend of this map it’s called No flow so basically there’s either intermittent reverse or no flow at all except for the Nile river which is getting through
Um and we will be talking about so the the outline is in two parts the first part is already published so I will do a bit fast on that because people can find the the details in the paper and the second part um I will hopefully have a bit more time
And this is unpublished and I’m very exciting to share that with you today because it would be good for me to have also feedback on that so um let’s start with the first part which is about the last 400 000 years basically I will reduce that a little
Bit I’m cheating there a bit um and this is about green Sahara faces and their climate drivers and expressions so I always like to show this picture when I talk about the green Sahara I’m pretty sure most of you here in the audience know very well what I’m talking about when
I’m I’m mentioning green Sahara but I always find it’s nice to hear about something we know very well from somebody else because it gives a kind of A New Perspective so I will give you mine um and this picture is really capturing the essence I think of of Queen’s our
Face is not this beautiful giraffe Engravings which are very big there are five meters they they were made over in Niger and they over a spot which is overlooking in ancient Lake where there used to be people um so now it’s one of the most arid
Places on Earth but it used to be giraffes and it used to be water and this has been dated at about 8 000 years ago so it’s the last of the green Sahara phase so and and graph so the cool thing is that there was this paper in 2011
Um with these very nice maps of how the green Sahara looked like probably with um mapping of uh Rivers River fans Lakes um but also um an inventory of um fossils or or artwork um and this is so this is for giraffe so what you see all these blue dots are places where
Um giraffes were were living and in the hash so you don’t see it very well but in the South so basically in the south of the Sahara you see a hashed um Zone and this is where this is the historical extent of giraffes so nowadays so you see that they were
Really living everywhere we were really in a different type of environment if I focus now on reverse so this is more or less the same map but just with the Freeview Network and I will talk about um what happened in Libya using a car that’s the red star and
So for those who don’t who are not familiar with with sediment course from the marine environment basically we go with a ship so now it was a pilarious that ship and we take a very long sediment tube using in some what we call a piston carrying gravity caring
And it’s a kind of very big syringe with a massive weight on top and the sediments are soft enough that you can basically let these massive tube so it’s it’s 11 10 to 11 meter along fall down in the sediments and the syringe then suck up the the sediments
With with very little disturbance so that’s a very nice technique to to to sample sediments and then you end up with these very long um PVC tubes which are cut in in one meter section and then cancel half in the lens opened and so what we saw with this car is um
Crazy colors stuff that I’ve never seen before in the Marine so everybody thinks it’s very very boring mud but in that case it was really beautiful we had really colors going from bright orange to very dark um black greenish colors and these are the proper layers which are very typical markers
Um in the Mediterranean and we can come back to that later on but I will not go any further for now but so this means that we have a quite nice stratigraphy in this car because because of the it’s a continuous deposition and we find this marker so we
Can date it pretty well um so then I took sediments I went in the lab so I’m dissolving sediments which means using acids that are not very nice so you have to be completely covered um after the sediments are dissolved I put them in these columns that we see in
The middle to separate elements and my elements uh for this car at least neodymium and strontium which are very nice provenance tray cells and I will show that to you in a moment once these sediments once these elements are separated from the rest extracted we can measure the isotopic composition
Using a multicolectomy spectrometer like the one we have here at the gift said foreign is how we use these Isotopes to um to track provenance the prevalence of sediments um so what is very specific in in in Libya and Tunisia is that you have in the south is very high
Um volcanic plateaus called um which are pretty young and have this specific side nature and this is uh highlighted with this red points on the map these are rocks taken there and they have this what we call radiogenic Signature and this can be also followed in freshwater Bible that were um collected
By one of my quotes are very long ago but she measured basically the uh neosinium composition of these divers and could see that there were also more radiogenic than all the dust formed around so this is a very nice tool to to discriminate between sediments coming from these volcanic
Plateaus and the dust which is very commonly brought to the Mediterranean so we did that we used this um so here I show you the strontium Isotopes um neodynamic stops were measure too but in that case I’ll show you the sponsor myself which are these black dots
Um they go up and down and um although the scale is inversed but we will disregard that for the moment basically when it goes up here so when it’s slow here um this means that we have radiogenic the radio genetic signature in the sediments and these can Will mostly come
From the Tibetan and Roger Plateau the other thing that we did is we measured the grain size and here I show you um and members and in green and yellow are the fine end members and basically what we see is that we have a combination of more radiogenic
Isotopes with very fine sediments and this is very different from what we know of the Dust being transported in this region so this is really tracking the reactivation of this river that we are able to bring sediment from the tbst basically to the to the coast and to the
Gulf of Seattle where we where we took the car so we see um here over the last 227 years um the recurrence of these faces of reactivation which lasts five to ten thousand years you also see on this um on the background of these curves that I have two different colors and I
Show you now the blue colors which are basically the domain integration faces and well we will talk about that in a minute um and then I will also talk about the green background which is a bit different so the next thing we did is we used the model
Which is great because sorry wrong um because it’s it was able to to make this long transient um modeling of precipitation over different regions and so I asked to be as an Excel to please provide me to two reconstructions once for the tea bestie Plateau so this this Central um Sahara High
Attitude plateaus and a box over the coast to see a little bit the interaction of these two precipitation regimes on the sedimentation and um this was basically very interesting so the first thing we saw is that so there’s a very nice match between this these these records and then we had to
Look a bit more in detail in the in the model in the in the seasonality of um of precipitation for instance during an integration so a faced a very strong precipitation over the tbst leading to the reactivation of these rivers and what we see is that we have a very long monsoon season
Over the summer but also probably extending in the autonomous some contribution from Autumn’s dump trucks so we have a very intense precipitation basically going all over the region and this has been reactivating all these rivers and basically all the water shed so not only the tea Festival also all what is in between
What it means also and this was already hypothesized by people before us is that these Rivers at least some of them were probably perennial because of this very long extended monsoon uh so that’s that’s a bit how it looks on the map I showed you before so we
Have a lot of rainfall over these high plateaus which a colleague of uh of of you actually uh Steph yet uh at the F Philly pulseman he called this plateau uh the water towers of the Sahara and it’s really working like that you bring a lot of rain you have these lakes and
They are able to to let river flows for a while in the glacier and so that’s this green background it’s a little bit different what we see that we have pretty fine sediments so we know it’s frugal um but the signature in terms of new genome and strontium is not as high as
In the integration so we have a kind of a mixed uh signal and uh then I I also I we did the same uh the same process we had a look in the precipitation special so special and temporal distribution of precipitation and what appears is that
We have mostly rain in autumn and winter but not so much in summer and especially not over the tbst so what what here there’s a bit of rainability but this is not enough to to have a continuous flow to the coast so our hypothesis is that basically we were
Reactivating some of the smaller volcanic fields which are located in Northern Libya so they bring this the signature of a bit more um radiogenic sediments and but also a lot of probably a lot of sentiments that were already deposited in the area which are less mediogenic so through the reactivation of
Um of wadis which are in that case known perennials probably um so yeah so that’s that’s it for for this car if you want to know more as I said there’s there’s a paper published and there’s a Blog as well and just yeah for for your information we are
Continuing this work now with the master student she will then make all the Reconstruction and two for 150 000 years which is nice we will have all the interrelations the warm integration she will also use the technology to link with other sites and I mean just get in
Touch if you if you have an idea I want to collaborate with us that’s still a lot to do but so I want now to to show you what I’ve been working on these past years and um we are going to focus on the last screen
Sahara phase so at the beginning of the whole scene and for that we are going to look in the Nile Valley um so I call it the Nile Laboratory um because you will see it’s really interesting the the type of results we can get and to to kind of
Um picture how this big Freeview systems might respond to uh warmer and water planets so here is again some some modeling data uh recent which showed that basically you get this very strong Monsoon and you get this large extent towards the nuts also because you have very warm temperatures at the surface
Um unfortunately there are not so many proxy records of of temperature of terrestrial temperature so it’s very hard to check that but this is what the model output was giving the other thing is also modeling a bit different now because it’s a forecast so it’s a it’s a comparison of historical
Data with a forecast using Smith 5 and all the choices you see on these curves are different models and the thick red curve is the average of all the models and the black are the actual data on the left side you have the runoff and on the right side you have the standard
Deviation so there’s two things happening that the others say there will be a larger so so the standard deviation of the runoff gives us an idea about the viability of the runoff and the others say there will be a stronger viability um due to uh due to a warmer climate
Um what I see here is a very very broad range of possibilities and a very very large entire model range so a large uncertainty basically and that’s where we can probably help with our proxy data so we are lucky enough to have this discover from the Nile deep sea fan
It’s a it’s a car that is six meter long and has almost five meters of fine laminations so I’m working on this car since a while but then it’s just really these past years that I decided to have a look in details at what these laminations are
Because nobody knew about it so we we knew more or less of the age but we didn’t know what kind of laminations there were so I’m now in this group in at the gift set which is specialized in vaft sediments and especially working on in lakes
So I use their techniques um to um to to characterized valves um on Discord and I went to sample throughout and did some sources so we these are some sediments so they have to be embedded in reason and we take thin sections and have a look at the chemistry and the microfacious
Basically I could recognize four different types of laminate which occur in in a very repetitive sequences Sometimes some of the laminis are absent but the sequence is always very very regular it’s always the same and in the same order what you see here is if you have a look
On the so you see all these nice colors and then there are some profiles and in between I have a log with different colors black orange yellow and gray these are the four different laminate just the black ones are the the summer floods they have a very specific faces and um and um
And chemical signature so we can talk about that later I will not go too much in detail now this has also be published um last year so you can have a look if you want to have more details and I can also explain a bit more um
But the thing is so I had already proposed that these were probably vast because of the of the very regular sequence that I could see but the only way to prove that is to have a look at the dating and the premise here we are in the floating valve chronology so we
Cannot say okay we start from zero and count down because the top of the car is not I mean it’s not laminated so I had to start from the top of my laminate in double and count all the way down so I can’t see these five meters or valves of
Laminations and then we had a look with a colleague who developed a program to um basically Um compare the the the accumulation rates that we get from the valve counting yeah um the ejaculation rates we get from the valve counting to the radiocarbon ages and here it’s really I mean it’s it’s almost textbook it’s working super well um the good thing is so this is called
She’s basically a kind of bacon but using a different type of prior and the cool thing is please mute yourself please thank you um and yeah so there’s a very nice match between the radio carbonages and our assumption that these are above so yeah we are pretty confident that we have a
We are in a bath system so basically after that I took my accounting and Mr chairman said it on the thicknesses and I put the thickness of the flood layer so this black layers I showed you and I I’m sorry put them on the age scale so
Excuse me so you have here the changes in layer thickness um between 7 509 500 usbp um and the other few things that I want to point out on this record so the the thick the thick line in the middle is the median and um the the two blue lines are the
Standard deviation two two Sigma Um so the first thing is there is a very I mean the the layer thickness is varying really drastically in this car we have a baseline of around one millimeter and in some places but sometimes this is more than doubled so we have then a baseline of 2.5 millimeters
So these are I so just so that you really picture these are thicknesses of individual layers deposited year after year on the Nile Delta so the the sediments come from the source of the nine and have been transported throughout the night they might have been remobilized in the way
That we cannot do but the the river was strong enough to deposit these these layers year after year and some of them are very very thick and you see the so the max is around seven millimeters and sometimes um we also cannot detect a layer so or
It’s just below the detection minutes so I could not really measure them I see them but they are not measurable they are very very thin so that’s the first thing very large variations the second thing is if we look at the accumulation rates we can detect change points through these
Records and these change points indicate moments that when the the thickness is changing pretty rapidly within 30 years so you have really throughout this car this records you have like shifts of the of the erosion regions sometimes you have very strong floods for a while and two you get into a different Baseline
With a different type of erosion strength basically um so what I did then is that I chopped up this record in using these change points identification and I had to look at the distribution of the thicknesses between these change points that’s what you see now at the bottom these
Different colors and the violin distribution what it tells us is that when we have very let’s say thin um mean or median thicknesses so relatively thin layers we also have a low distribution like a very reduced range of distribution whereas when we have these thicker layers we also have this complete flip
Flop between very thin layers and very thick layers so a very broad range of distribution so we are in the in in a system which produces extreme floods or is able to produce very very strong fluids but it’s also flipping very fast so the next step was to have a look what
Is driving this um very strong changes and because we have this annual record we can also do a Time series analysis so I did a wavelet analyze on this on this record and what is very clear is that we have and this is this is known for the Nile at present
And also at historical times so this is not really a surprise but it is interesting to see that enso is a very strong pacemaker for this record it is driving most of the of the variants that we see and what is interesting in that case is
That we can say that also for warmer and wetter climate Enzo Remains the main pacemaker um so it is it is a kind of a good news because it means that if we can predict them so we can partially predict what will happen in the industry of in this In this River
So then we use also a model um that Monica runs and the cool thing is they have simulations at 9k which normally here modern doesn’t like so much because they are still some ice sheets remaining and they prefer to to take 6K then but they have 9k so we can have a look
So this is precipitation anomaly um so no surprise there’s a very strong anomaly of precipitation around North East Africa what is cool is we can also have a look in the ssts and what we see is that we basically innocent this is summer we have a strong
SST animal very similar to what we see during la nina events so yeah that’s it for now um to sum up we so we confirm what actually the modelers saw already with uh with in the cmit five simulations that warmer climates probably will lead to higher through your liability
We also can confirm that Enzo is a pacemaker and we will continue to be so in in different types of climates and probably with uh shifting to laminating conditions that might be very specific to the early volunteer we can discard that um we still have open questions so for
Instance we see that so enso viability gets also so the notes it’s not that the the viability of night floats based by enso gets also very strong um so more viable and we don’t know if this is due to a more viable and so because this is very hard to to model or
Is it due to a local amplification of an Enzo signal which has remained actually pretty stable that is still a question um also we don’t really know what drives this very rapid shifts so this you know these change points these moments where we have shifts in in the river region
That is still a bit of a question we don’t we don’t really know but this is also complex so yeah so I’m I’m done I’m I was a bit longer I hope it’s okay and I’m happy to take any questions all right thank you so so much Cecilia
That was a wonderful presentation you are perfectly perfectly on times please do not worry at all um I’m I would be opening um like the presentation for a question from the audience if that is okay so if anyone want from the folks listening wants to jump in with the question
Please go ahead you can also write it in the chat and I’m gonna just read it out or something so anyone want to go first yes anyone no because if not then right okay well otherwise I would have done it so go ahead I have a question so
Um at the top of your your record you lose the laminations what do you think the reasoning is for that like do you know yeah um so basically what you what you saw I didn’t say because I didn’t want to talk too much actually um it’s it’s a problem it’s an
Expression of it’s a profile it’s called uh laminates so some of the separables are laminated this is just an extended sub property which also propels the the the principle is that you bring so much fresh water in the in the in the Mediterranean that you block the the
Circulation in the military name so there’s no Oxygen at the bottom and which means no burrowing so you preserve basically this stratification as soon as you start reventilating the Mediterranean at the end of the African human period you start also recovering your your bentic habitats and and biotabating your sediments and that’s
Basically what you what you see and that’s also why we don’t have laminations anymore after seven seven thousand years okay cool if you looked at a call somewhere else would you be able to find those laminations like is it just they’re recorded somewhere else yeah so
They have been found and they have been found in different places in the Mediterranean you have to have specific type of environments and she doesn’t come you can also say something about it um but basically there have been fun also for all the subropets so not only
For this one it’s just that nobody download that extended this is this is a bit unique because it’s five meters thick so it’s really so much sediment um it’s really so when I was looking at the sediment you really have these very thick layers very very thick so in just
In terms of sensing the El Nino signal the Enzo signal do you think so it’s really it’s not that the enso signal is not there it’s just that it’s not record it’s not recorded at that particular location um yeah what’s the it is there it’s it’s
Actually the main pacemaker so it is it is really I mean the fingerprint is very very clear but in the older part of the record but where you lose yeah sorry oh I can show you something actually because it’s that’s that’s how I started doing it I will I will just uh scroll
Through my I will just show you it’s a bit more so it doesn’t look as nice as what I showed you but this is a bit older it doesn’t matter um what’s super interesting with the Nile is that there are these uh fantastic recordings of the nylometer so basically ancient Egyptians were
Measuring the level of the Nile year after year during the historical period and uh so this is a this is actually we have a kind of equivalent of this but for the African Union period uh and people who have been working on on this record of the nilometer so they
They harmonized it and um and had a look at the uh at the time time series uh in in this record and they saw the same basically they saw this very strong influence of Enzo also at historical times and I’m saying that because then we are
We are in a different type of uh climates so this is the late Holocene Common Era um so we don’t have these massive floods that I see in the African in the period it’s much more calm but you still are following answer nice super cool yeah I
Mean ties up with the stuff that Stephanie I’ve been thinking about as well so yeah really really nice so thank you very much someone raised their hand I hope I’m doing the name Justin did Jack Jack is that is that anyone here I’m so sorry I’m butchering the name I’m apologizing sorry
You are mute you have to unlock yourself yeah perfect go ahead hello everybody you know I hope that you can hear me now yes perfect yeah uh I I first want to apologize because I could not follow all the old presentation because I was driving I shift from the phone to the computer
Another geologist in Mali western Africa so I’m working also at the same perhaps the same type of sediment but in the suffered suffered part of the Sahara and what I saw is about the laminations and I found the same laminations here in Mali and we have um we are working on on the
Psychographical profiler of about 40 meters with the same lamination and I’ve been thinking that there is maybe a link between those dominations and the seasonality of the of the climate because we here with our tropical climate and we have some deposit at the beginning of the rainy season
And some some deposit during the rainy season so it’s not one lamination per year but it’s it’s about uh more elimination together to follow one year I don’t know if you saw the same pattern in uh and that you are you are working on and also about the floods because uh if
I I didn’t know I I see that I did not follow all the presentation but I was thinking about the floods did you were you able to differentiate between uh the deposits during normal years and the deposit during flooding years because there is a difference between the difference of type of sediment when
There’s a floating and in normal year yeah we are also expecting to have some some alien aeolian sediment sediment from uh wind driven sediment yeah were you able also to make a kind of a differentiation between those types of signals yeah absolutely yeah yeah totally right I
Didn’t spend any time in showing really in details these laminations um so here and here is not very detailed but you can see already a little bit so basically you have these different layers with different colors and I see four different types of laminate of laminates of individual type of
Deposition with different with different microfacials and um which corresponds to different seasons as well so basically what is what is very interesting here as you see for instance that after every uh flood layer you have a bloom in the in the position of shoulder knife basically because you are bringing so much
Nutrients and there are I even found some old papers of I think 60 something before the the building of the aswanda where they could see that this was a seasonal process and that you had so much nutrients after the night that you had some Fisheries for instance that
Were operating only during the autumn so this is already a known a non-seasonal um process and so you have and and indeed I think the deposition of the flood so the the type of microfacials you have in the flood is different than what we see so
Then you have a flood you have this Bloom and then you have Sometimes some dust when you see really individual gray the grains of quartz which are much thicker and then sometimes and then you have this layer of very fine sediments so it’s really clay and this is most
Probably what happens in the winter when you still have some flow in the line but this is not a flood this is just very and this is the same with people who have studied sediments in the Nile uh have seen these different ingrown size between the flood and between the the winter origin
And then there’s something happening but it’s a bit more complicated it’s a kind of carbonates that form in the probably in the water because the conditions the the chemistry of the water is so weird because there’s no Oxygen or whatever but that’s something a little bit different and I don’t think
It makes sense but it’s very interesting so you said you found that in in Mali and is it a lake or is it a Paleo lake or yes in Mali we have we have discovered the Paleo Lake I’m actually I’m working on the quaternary history of the Niger River in
Mali so we have found that before the Nigeria River in the area of bamako we had the Paleo lakes and we are working on the deposit of the this part of it and we are seeing the kind of features that you are you are showing okay even
The cabinets also we we found them also in the deposit yeah in Lakes it’s very often again yeah thank you I don’t know maybe it may be later we send we send to you the the some of the pictures that I have please do get in touch it would be
Extremely interesting and you also you can send me some I would try to find did you do another a different another type of analysis on the forklift differentiate the the floor deposits because I think that maybe it may be using the CN the CN ratio ratio maybe you can try to discriminate
A little bit between them yeah so I have I have done this kind of measurements but on a lower resolution not on this type of reason now what we we have here in in Germany a group in Bremen who is looking at biomarkers in uh in in nominations as well and they
Took some samples from this car so we will have a look whether we have a side note but it’s you have to have a certain amount of organic matter if you want to have a good cycle so we still not know um and and then because we had this
Comment already from people that a nice way to to trace this is to look at green size changes that’s really a way to to evaluate how strong your River was yeah but this is again very hard to do on uh on such a resolution so we will try to
Do a prediction using uh using xrf that’s that’s a master student we will work on that as well in the coming months I think it’s kind of interesting because it’s a color we have so much data so it’s actually quite nice but yeah please do get in touch it would
Be very normal I will I will try yeah I’m sorry thank you so much um so there’s another question from Neil why don’t you go ahead oh uh hi great talk um I wonder what how much she knew about the modeling did love Clinton produce
The uh the whips uh the uh wet Sahara endogenously or do they have to um uh create that somehow and what what kind of vegetation is there in the model and what do they find I’m not sure whether love team is very good for vegetation I don’t think so
A lot of Kim is super because it makes this very long-trans and simulations that are needed for this time intervals um but the the special resolution is pretty cost so there’s no topography for instance we had really primes and so for the tbst you cannot look at
Um yeah at too much detail because there’s there’s barely a needable worship this is a problem um and also the the temporal resolution is every Thousand Years um so these are very long these are very long simulations but not super precise and I’m not sure if love
Team is very good with I don’t think they are very good I think some of the models are doing better with with vegetation like the the MPI models for instance are better I think what Martin Klausen is using but you don’t know whether it produced The Green Sahara
At the right moment endogenously it does it does we did check for so we did check for the for the amount check for the is well captured so at least where we could compare with with present data where there is actually some rain because the prime of the central Sahara nowadays it’s
Extremely dry so yeah okay yeah but only because we could compare the finality and it’s and it’s it’s fine on that level so it’s it is capturing it relatively well it’s just I think if you want to do something very precise this is not the right model
But I’m once again I’m not a modeler so okay thanks okay thank you so much um I have a question if I can squeeze myself in um the mechanism you proposed with the answer that’s as you said that’s not a shocker so I’m happy to see
That what I’m I somewhat puzzled is the face of the answer you’re proposing for the simple reason and correct me if I getting all the literature wrong but the particularly the East African strength or strengthening is usually associated with the El Nino phase not the line in your face which is supposed
To favor the other side of the continent to a much greater extent so considering that you can find this in the eastern African long-term records that pattern my question would be why do you propose it’s on that time scale learning yeah not El Nino um so actually so here we are attaching
To a point which is uh difficult because we are looking at Ethiopia and Ethiopia is very um heterogeneous and so in the south you have what you say so you have and it’s and it’s not the same it’s not the same precipitation regime no it’s mostly driven from the
Indian Ocean and and so forth what we are looking at is read the monsoon and so this is basically very seasoned face with the West African uh African Monsoon and uh in in Ethiopia um and especially the night in the night region in nice sauce the and so leads to very dry conditions
And La Nina to very wet conditions which is the opposite in the south of Ethiopia so this is sometimes a bit contentious because if I let’s say if I take the cheaper Hall record like I I can only make the argument on the long periods of time because that I know myself
And so it’s an annual things and I understand that but the general pattern of the worker circulation change it underlies it works on on Orbiter time scale as it does on very small time scales and if you look at the chopahar record which is more or less a part of
The Nile catchment that record and the null discharge actually aren’t phase multi-child was able to show that that these two records are heavily correlated towards it to uh with each other um that they have a similar um variability you use recurrence plots to show that so they have a similar
Facing and that record runs also on interfaces but it’s in Phase with El Nino not La Nina so I get your point but on longer Orbiter time scale I could make the exact opposite argument so maybe it’s worthwhile to check the cheaper High record because that record
Has actually resolution at least to some extent for the Holocene it’s one of the best high resolved records that are in East Africa and it does have good and so I know I know this uh but it’s not it’s it’s not an annual recall no it’s not
It’s just well I’m looking so honestly I I I think what I’ve been doing is just looking at the present day and historical data as an analog um because there I mean all the rest is is speculation you know if you don’t have an annual record you cannot see your your answer fingerprints
And then you cannot have a look at what is driving your your cycle I think that is that is why disregard is particularly interesting is that we do have that and so we can start looking at what is driving these very strong monsoons that is very strong floods that we see and
What kind of process is driving that and and based on what we know from the present pencil is is leading to very dry conditions um it’s also what you said it’s a social security I completely agree there’s no other archive if you want to keep the same time scale that okay but
Well but I I just like because the stuff that is that it’s usually based on more on observational data and that is annual resolution so the argument you can make like if you look at the work by um Nicholson that is annual resolve data observational data for the last 30 40 50
Years and that shows the same thing on average so so so what she for for the for the night what she says and then she’s not the only paper for the night alone there are many that that’s that’s that’s Enzo is is driving uh I mean is
Is associated to uh to droughts in this region and not to uh to floods so I mean sure you can check it but it’s a no in in in the night it’s very clearly um there’s a very clear link between La Nina conditions and very strong precipitation and floodgers so basically
All these like in Sudan all these very strong floods happen during the Nina events um and so that’s why I’m saying that I think what I see and that’s also what we see in this MPI NSM model that these are mostly linear conditions but that’s why
I think that’s where the analogy is very shaky because the type of warming we get due to an orbital forcing is very different to the type of warming we get from greenhouse gases and so we cannot choose this as an analog that is very clear so this um it’s it’s interesting to go
To a certain extent in in term of analogy but there we need to be very careful because from what I know most models predict that it’s gonna go into and so and so stronger and so rather than Stronger Yeah but this is again very debated models are saying different things so
I’m not that you know I’m not arguing on that but this is not my fiend of expertise but uh yeah so I’m just using you know what we have and um doing the best of it but I will I will have a look again into uh into I I
Remember having a nuclear just that I have it’s very hard to find uh Records on assumptions completely agree like totally see your pointer so maybe it’s worth to look at and you can always throw it out if it doesn’t pan out like in in a way it
Would require it to be so it was just a thought yeah it might actually be I mean it’s I think it’s there’s still a lot of work to do and it’s actually probably the next like where you know like the other thing I was thinking on if I can just
Kind of like squeeze in what that even though it may be a long stretch to look at the outflows records because those have extremely high resolution it’s not annual I completely agree but we know that we have um the answer frequencies in there we do have at least the long the somewhat
Longer periods we do have them in those records and these records have resolution right like the XF data has theoretically a resolution of 30 years so um no no the military and outflow records from the Gulf of Cadiz they have these records have roughly 30 years or less or or higher resolution
Than that so it’s still maybe also long shot but I know from spectral analysis that I did during my phds at the ends of frequencies are in there at least a longer not the annual so 100 because the the end so frequency set two and four years so no it’s the long-term
Pattern that you can start picking up that is more on a the cable mode like if you look at observation data it follows also a decable mode that you can start picking up if you have a record that has within a couple of Decades of resolution
But again it might just be a long shot I was just singing because it has such a sensitivity what goes out to what’s happening to the Nile region it’s maybe just a brain forward and it’s not going to pan out at all but no we didn’t know I mean that that’s not complicated
That’s I mean everything is there the data is there so perhaps it will be interesting when we if we succeed to uh predict the brain size that will be more comparable I think but yeah totally like if you have somewhat slightly better like more resolution
That goes to what is in the outflow is just the outflow is super sensitive like you dump a bucket of fresh water in the catchment and basically the outflow is having hiccups it’s a super sensitive system in my personal View and the record up there so if you if you just
Like want to look into that it might be worth it just just for for a few minutes hmm yeah sure maybe we can chat anyway and sure so now I have basically monopolized you for quite some time so are there any more questions from other people that I cheated out of the opportunity
Everybody stand yes because of the awesomeness it was this presentation so if there is nobody else so they’re like a half a dozen like thank you this is a really nice talk in the chat you can check it out if you like um so thank you again very much for this
Really nice talk oh there is one more question I’m sorry Jack go ahead foreign Between the sediment and um the rainfall data and we are doing a kind of work here to try to make calibration with three three rings first because the data we have from the methodological Association are not very precise very irreliable so we are going to do this kind of calibration first and
Then we try to to compare to apply this to the sediments and the frame size analysis you are talking about I think that you you will have to take into account many many parameters because the ground size can change not only because of floods or water uh whatever
So it’s important to take this into account and I have I think that you are going to close I wanted to confirm those UMR so that we have here in Mali we have open a Master Degree in quaternary quaternary climate change and quaternary environmental reconstruction we have 22 students graduate students
Now now doing the master degree in quaternary so I wanted to give to you this information okay that doesn’t so so um do you have my email I think it was in yes should I put it in the in the chat and we can then perhaps chat a bit more later on okay
Here you go so you can you can just get in touch and then we can we can chat and I’m very happy to chat brother oh yeah perfect are we just I will quickly paste it super thanks that’s awesome um are there any other questions I don’t
Want to cut off anyone but we are closing in on our hour so I don’t wanna overdo it with the time I know everybody’s super busy if not then again really like thank you very much for coming online doing this extremely nice presentation it was super interesting I’m really looking forward
To seeing the data that’s coming out like I think everybody else too um I don’t know we will help me when is the next talk it’s in in March I think the archaeologists are coming online right I have it right here 16th of March um at uh same time slot
Um just in Partridge to Tyler Faith Brian Stewart um the potentials and pitfalls of linking climate and cultural change with a focus on the archaeological record and Lin quick will be chairing that one so more information will be circulated uh around for everyone for that seminar
Coming soon so please join us there also a quick plug we have now the mapping ancient Africa meeting ahead of the inqua Congress to the two days before the Inca Congress that is kindly funded by palcon um and uh we get free rooms and we’ve
Got that so please if you’re going to be in inquest come come early and spend two days plotting mapping ancient Africa stuff uh with us uh in in Rome that would be great I have a little question regarding that I’ve seen that passing by I’m not sure if I will make it
Um so will it be also hybrids that’s question number one and question number two uh do we want to organize perhaps an event in the evening good question part one of the question is I think elements will be online during the the idea is to have four different
Sessions during the two days dealing with various aspects of Publications writing and the future of of the project how are we going to take this forward uh we’re going to apply for more inquiry funding how we’re going to do that who is going to do that um I think the
Evening of the first day of the workshop which I think is the 12th it would be nice to organize something for people who are there the evening of the 13th is the Icebreaker for inquir so I think that probably the evening after the first after the second day of the workshop we will
Um we’ll we’ll go to the the ink Icebreaker and get the registration and get started with that um and during the Congress we obviously have the map in ancient Africa sessions we have two sessions um which is great we weren’t allowed any more slots we thanks to everybody who
Submitted we gave as many people talks as we could um and we have I think 16 talks and 20 odd posters uh lined up for the session uh I did ask them for another session slot to have another eight talks but I didn’t get any response with that
Um so I think that really shows the the enthusiasm for this and the excellent research that’s going on so I look forward to catching up with as many people as possible um in Rome me too looking forward to so if you need more information just contact either
Willow me and we’re happy to supply you with as much information as we can at the moment um so in that case I wish everybody a wonderful evening morning or wherever you are on on the planet so have a good one thank you fancy seal for making the nice presentation and hopefully catch
You up in March before they are colored archaeologists bye bye