how much dust? and which dust? · a conceptual estimate of potential consequences 0.001 1 100 0.0...
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![Page 1: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/1.jpg)
How much dust? And which dust?
From grain-size data (and bulk density)to aeolian mass fractions
Michael Dietze1
1 - GFZ German Research Centre for Geosciences, Section 5.1 Geomorphology
![Page 2: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/2.jpg)
A (more or less) typical loess section
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 3: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/3.jpg)
A (more or less) typical loess sectionA (more or less) typical loess section
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 4: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/4.jpg)
A (more or less) typical loess sectionA (more or less) typical loess section
0.001 1 100
0.00.5
1.01.5
2.02.5
3.0
size(µm)
Vol.-
%
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 5: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/5.jpg)
A (more or less) typical loess sectionA (more or less) typical loess section
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 6: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/6.jpg)
A more conceptual formulation of the problem
dust(s)
other
proxi-mal
distalre-
mote
1. How much solid is there?
2. How much of it is "dust"?
3. Which types/sources are there?
4. What are its average densities?
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 7: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/7.jpg)
A conceptual estimate of potential consequences
0.001 1 100
0.00.5
1.01.5
2.02.5
3.0
size(µm)
Vol.-
%
"dust fraction" Cutting off at fixed boundaries may lead to:
- underestimation of the target fraction's total vol.-%
- contamination of the target fraction, by - tail(s) of coarser fractions - contribution of smaller fractions
- bias in the resulting time series of dust
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 8: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/8.jpg)
5e−02 5e−01 5e+00 5e+01 5e+02
01
23
45
Grain size (µm)
Vol.−
%
0 20 40 60 80 100
020
4060
8010
0
Time/sample IDR
elat
ive c
once
ntra
tion
A simple test of the contamination hypothesis – Setup A
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 9: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/9.jpg)
A simple test of the contamination hypothesis – Setup B
5e−02 5e−01 5e+00 5e+01 5e+02
01
23
45
Grain size (µm)
Vol.−
%
0 20 40 60 80 100
020
4060
8010
0
Time/sample IDR
elat
ive c
once
ntra
tion
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 10: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/10.jpg)
A simple test of the contamination hypothesis – Resulting mixed data sets
5e−02 5e−01 5e+00 5e+01 5e+02
01
23
45
Grain−size
Vol.−
%
5e−02 5e−01 5e+00 5e+01 5e+02
01
23
4
Grain−sizeVo
l.−%
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 11: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/11.jpg)
A simple test of the contamination hypothesis – Resulting "dust" fractions (< 4 µm)
0 20 40 60 80 100
020
4060
8010
0
Time/sample ID
Rel
ative
con
cent
ratio
n
0 20 40 60 80 100
020
4060
8010
0
Time/sample IDR
elat
ive c
once
ntra
tion
true fraction
apparent fraction
true fraction
apparent fraction
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 12: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/12.jpg)
One approach to tackling the problem – parametric curve fitting
5e−02 5e−01 5e+00 5e+01 5e+02
01
23
4
Grain−size
Vol.−
%
µ1, σ1, c1µ2, σ2, c2µ3, σ3, c3
Fitting n parametric distributions (log-normal, Weibull, Gamma, ...)
Attractive, because we get unmixed time se- ries and parametric end-member definition
But, for each sample we can get different µ, σ. So which one is the right one?
What if a sample has more than n compo- nents, or less?
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 13: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/13.jpg)
Another approach to tackling the problem – eigen space based decomposition (EMMA)
Considers an entire data set as input and describes it as linear combination of eigen vectors (V) and their scores (M) plus an error matrix (E).
Based on eigen space decomposition (PCA), extended to optimisation and reduction (FA), framed by scaling to real units (EMMA).
Attractive, because we get unmixed time series and unconstrained end-member definition
MX
V
X = M V + E• T
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 14: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/14.jpg)
Another approach to tackling the problem – eigen space based decomposition (EMMA)
Lumi-nescence
RLumModel
BayLum
ADmin
sandbox EMMAgeo PUMAgeo
RLumShiny
rbacon
Basic and advanced data analysis
Luminescence model implementation
Bayesian age calculations
Bayesian age depth models
Advanced age data visualisation
Age error type separation
Virtual sediment section modelling
Compositional data analysis
Age-depth to proxy uncertainty propagation
Bchron
clam
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 15: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/15.jpg)
Another approach to tackling the problem – eigen space based decomposition (EMMA)
FAPCA
EMMA
Online course: micha-dietze.de/pages/r_courses.html
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 16: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/16.jpg)
Another approach to tackling the problem – eigen space based decomposition (EMMA)
0 5 10 15
0.0
0.4
0.8
Class−wise explained variance (mean = 89 %)
Class
R2
0 20 40 60 80 100
0.85
0.95
Sample−wise explained variance (mean = 97 %)
Samples
R2
0 5 10 15
01
23
45
67
End−member loadings
Class
Rel
ative
am
ount
s
5 15 25 35 45 55 65 75 85 95
End−member scores
Samples
Rel
ative
am
ount
s
0.0
0.2
0.4
0.6
0.8
1.0
End−member ID (mode position | explained variance)EM1 (6.1 | 23 %) EM2 (4.7 | 19 %) EM3 (1.6 | 30 %) EM4 (1 | 28 %)
0 5 10 15
0.0
0.4
0.8
Class−wise explained variance (mean = 89 %)
Class
R2
0 20 40 60 80 100
0.70
0.85
1.00
Sample−wise explained variance (mean = 93 %)
Samples
R2
0 5 10 15
01
23
45
67
Robust end−member loadings
Class
Rel
ative
am
ount
s
Robust end−member scores
Samples
Rel
ative
am
ount
s pe
r end
−mem
ber
0 20 40 60 80 100
00
00
End−member ID (mode position | explained variance)EM1 (64 | 14 %) EM2 (74 | 27 %) EM3 (98 | 26 %) EM4 (100 | 33 %)
Deterministic mode ("I know the number of components") Robust mode ("I fully allow for parameter uncertainty")
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 17: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/17.jpg)
Let's apply the technique – Welcome to a special kind of dusty deposit
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 18: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/18.jpg)
Let's apply the technique – Welcome to a special kind of dusty deposit
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 19: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/19.jpg)
Let's apply the technique – Welcome to a special kind of dusty deposit
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 20: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/20.jpg)
Let's apply the technique – Welcome to a special kind of dusty deposit
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 21: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/21.jpg)
Let's apply the technique – Welcome to a special kind of dusty deposit
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 22: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/22.jpg)
Let's apply the technique – Welcome to a special kind of dusty deposit
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 23: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/23.jpg)
Let's apply the technique – Welcome to a special kind of dusty deposit
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 24: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/24.jpg)
Let's apply the technique – Welcome to a special kind of dusty deposit
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 25: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/25.jpg)
So?... Some recapitulation ... And a look ahead
Aeolian deposits usually comprise a mixture of components from different sources, transport pathways and transport processes, and have undergone syn- and postdepositional alteration.
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 26: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/26.jpg)
So?... Some recapitulation ... And a look ahead
Aeolian deposits usually comprise a mixture of components from different sources, transport pathways and transport processes, and have undergone syn- and postdepositional alteration.
Simple, subjectively defined size boundaries inevitably introduce bias, which is why we need robust approaches to unmixing data into inhertent components.
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 27: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/27.jpg)
So?... Some recapitulation ... And a look ahead
Aeolian deposits usually comprise a mixture of components from different sources, transport pathways and transport processes, and have undergone syn- and postdepositional alteration.
Simple, subjectively defined size boundaries inevitably introduce bias, which is why we need robust approaches to unmixing data into inhertent components.
After a decision which components represent the "dust fraction(s)" of interest, it is crucial to investigate the spatial heterogeneity (or spatial autocorrelation function of the data).
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 28: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/28.jpg)
So?... Some recapitulation ... And a look ahead
Aeolian deposits usually comprise a mixture of components from different sources, transport pathways and transport processes, and have undergone syn- and postdepositional alteration.
Simple, subjectively defined size boundaries inevitably introduce bias, which is why we need robust approaches to unmixing data into inhertent components.
After a decision which components represent the "dust fraction(s)" of interest, it is crucial to investigate the spatial heterogeneity (or spatial autocorrelation function of the data).
With spatially "scaled" volume percentages of distinct dust fractions, one can engage with i) removing the non-solid volume fractions (water, air), ii) propagating solid volumes to age-depth-space, and iii) robustly estimating size- and component-specific material density, to produce mass deposition rates.
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 29: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/29.jpg)
So?... Some recapitulation ... And a look ahead
Aeolian deposits usually comprise a mixture of components from different sources, transport pathways and transport processes, and have undergone syn- and postdepositional alteration.
Simple, subjectively defined size boundaries inevitably introduce bias, which is why we need robust approaches to unmixing data into inhertent components.
After a decision which components represent the "dust fraction(s)" of interest, it is crucial to investigate the spatial heterogeneity (or spatial autocorrelation function of the data).
With spatially "scaled" volume percentages of distinct dust fractions, one can engage with i) removing the non-solid volume fractions (water, air), ii) propagating solid volumes to age-depth-space, and iii) robustly estimating size- and component-specific material density, to produce mass deposition rates. Thanks
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 30: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/30.jpg)
DARTDust Accumulation Rate Tackling
Thanks
THE PROBLEM | ONE SOLUTION | ANOTHER SOLUTION | APPLICATION | SYNTHESIS
Michael Dietze @ GFZ Potsdam > Geomorphology Section > Sediment unmixing > Workshop on dust mass accumulation rates
![Page 31: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/31.jpg)
![Page 32: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/32.jpg)
![Page 33: How much dust? And which dust? · A conceptual estimate of potential consequences 0.001 1 100 0.0 0.5 1.0 1.5 2.0 2.5 3.0 size(µm) Vol.-% "dust fraction" Cutting off at fixed boundaries](https://reader035.vdocuments.us/reader035/viewer/2022063012/5fc9d7d00487c725ec11fc7e/html5/thumbnails/33.jpg)