itexpand methods text - cosmo - front and backend for Markov-Chain Monte Carlo inversion of cosmogenic nuclide concentrations Err mx1.adamsgaard.dk 70 hgit clone git://src.adamsgaard.dk/cosmo URL:git://src.adamsgaard.dk/cosmo mx1.adamsgaard.dk 70 1Log /src/log.gph mx1.adamsgaard.dk 70 1Files /src/files.gph mx1.adamsgaard.dk 70 1Refs /src/refs.gph mx1.adamsgaard.dk 70 1README /src/file/README.md.gph mx1.adamsgaard.dk 70 1LICENSE /src/file/LICENSE.gph mx1.adamsgaard.dk 70 i--- Err mx1.adamsgaard.dk 70 1commit c61d24deab6ce81dcb4e8b538cab571d035beb2e /src/commit/c61d24deab6ce81dcb4e8b538cab571d035beb2e.gph mx1.adamsgaard.dk 70 1parent f10b964bf2b108b2bfdb8e7fe509f1731af47984 /src/commit/f10b964bf2b108b2bfdb8e7fe509f1731af47984.gph mx1.adamsgaard.dk 70 hAuthor: Anders Damsgaard URL:mailto:anders.damsgaard@geo.au.dk mx1.adamsgaard.dk 70 iDate: Fri, 27 Nov 2015 14:26:03 +0100 Err mx1.adamsgaard.dk 70 i Err mx1.adamsgaard.dk 70 iexpand methods text Err mx1.adamsgaard.dk 70 i Err mx1.adamsgaard.dk 70 iDiffstat: Err mx1.adamsgaard.dk 70 i D matlab/output/.DS_Store | 0 Err mx1.adamsgaard.dk 70 i M pages/methods.html | 76 +++++++++++++++++++++---------- Err mx1.adamsgaard.dk 70 i Err mx1.adamsgaard.dk 70 i2 files changed, 52 insertions(+), 24 deletions(-) Err mx1.adamsgaard.dk 70 i--- Err mx1.adamsgaard.dk 70 1diff --git a/matlab/output/.DS_Store b/matlab/output/.DS_Store /src/file/matlab/output/.DS_Store.gph mx1.adamsgaard.dk 70 iBinary files differ. Err mx1.adamsgaard.dk 70 1diff --git a/pages/methods.html b/pages/methods.html /src/file/pages/methods.html.gph mx1.adamsgaard.dk 70 it@@ -16,15 +16,31 @@ Err mx1.adamsgaard.dk 70 i Constraining the landscape history and past erosion rates in Err mx1.adamsgaard.dk 70 i previously glaciated terrains is, however, notoriously Err mx1.adamsgaard.dk 70 i difficult because it involves a large number of unknowns. Err mx1.adamsgaard.dk 70 i- The potential use of cosmogenic nuclides in landscapes with Err mx1.adamsgaard.dk 70 i- a complex history of exposure and erosion is therefore often Err mx1.adamsgaard.dk 70 i- quite limited. Here, we present a novel multi-nuclide Err mx1.adamsgaard.dk 70 i- approach based on the Markov Chain Monte Carlo (MCMC) Err mx1.adamsgaard.dk 70 i- technique. The model framework currently incorporates any Err mx1.adamsgaard.dk 70 i- combination of the following nuclides 10Be, Err mx1.adamsgaard.dk 70 i- 26Al, 14C, and 21Ne, and is Err mx1.adamsgaard.dk 70 i- highly flexible. Err mx1.adamsgaard.dk 70 i-

Err mx1.adamsgaard.dk 70 i+ This webpage uses an approach based on the Markov Chain Err mx1.adamsgaard.dk 70 i+ Monte Carlo (MCMC) technique. The model framework currently Err mx1.adamsgaard.dk 70 i+ incorporates any combination of the following terrestrial Err mx1.adamsgaard.dk 70 i+ cosmogenic nuclides (TCNs) 10Be, 26Al, Err mx1.adamsgaard.dk 70 i+ 14C, and 21Ne in order to constrain a Err mx1.adamsgaard.dk 70 i+ two-stage glacial/interglacial history at the site of Err mx1.adamsgaard.dk 70 i+ sampling.

Err mx1.adamsgaard.dk 70 i+ Err mx1.adamsgaard.dk 70 i+

The MCMC technique is used to simulate TCN concentrations Err mx1.adamsgaard.dk 70 i+ associated with a large number of different Err mx1.adamsgaard.dk 70 i+ glacial-interglacial histories, including highly varying Err mx1.adamsgaard.dk 70 i+ glacial and interglacial erosion rates. Based on comparisons Err mx1.adamsgaard.dk 70 i+ to measured concentrations, it is possible to determine the Err mx1.adamsgaard.dk 70 i+ most likely landscape history and associated uncertainties. Err mx1.adamsgaard.dk 70 i+ Err mx1.adamsgaard.dk 70 i+

Err mx1.adamsgaard.dk 70 i+ The model approach approximates the values Err mx1.adamsgaard.dk 70 i+ and uncertainties of four output parameters; Err mx1.adamsgaard.dk 70 i+ interglacial erosion rate (εint), Err mx1.adamsgaard.dk 70 i+ glacial erosion rate (εgla), time of Err mx1.adamsgaard.dk 70 i+ last deglaciation (tdegla), and the Err mx1.adamsgaard.dk 70 i+ climate threshold value in the marine oxygen-isotope Err mx1.adamsgaard.dk 70 i+ record (δ18Othreshold) at Err mx1.adamsgaard.dk 70 i+ the site of sampling. Err mx1.adamsgaard.dk 70 i+
Err mx1.adamsgaard.dk 70 i Err mx1.adamsgaard.dk 70 i

In the following we give a basic overview of the applied Err mx1.adamsgaard.dk 70 i methods and their application. For a full description see Err mx1.adamsgaard.dk 70 it@@ -48,7 +64,19 @@ Err mx1.adamsgaard.dk 70 i

Err mx1.adamsgaard.dk 70 i

Err mx1.adamsgaard.dk 70 i Two-stage glacial-interglacial model

Err mx1.adamsgaard.dk 70 i-

bla bla

Err mx1.adamsgaard.dk 70 i+

The model concept builds on the assumption of a Err mx1.adamsgaard.dk 70 i+ "two-stage uniformitarianism", meaning that the processes Err mx1.adamsgaard.dk 70 i+ that operated during the Holocene also operated during Err mx1.adamsgaard.dk 70 i+ earlier interglacials with comparable intensity. Likewise, Err mx1.adamsgaard.dk 70 i+ the erosion rate during the past glacial periods is assumed Err mx1.adamsgaard.dk 70 i+ to be comparable.

Err mx1.adamsgaard.dk 70 i+ Err mx1.adamsgaard.dk 70 i+

The model approach assumes that glacial periods were Err mx1.adamsgaard.dk 70 i+ characterized by 100% shielding and no exposure, which would Err mx1.adamsgaard.dk 70 i+ require more than 10 m of ice thickness for production due Err mx1.adamsgaard.dk 70 i+ to spallation (>50 m for muons). Interglacial periods are Err mx1.adamsgaard.dk 70 i+ assumed to have been characterized by 100% exposure and zero Err mx1.adamsgaard.dk 70 i+ shielding.

Err mx1.adamsgaard.dk 70 i
Err mx1.adamsgaard.dk 70 i Err mx1.adamsgaard.dk 70 i Err mx1.adamsgaard.dk 70 it@@ -71,20 +99,20 @@ Err mx1.adamsgaard.dk 70 i

You may use the following BibTeX entry:

Err mx1.adamsgaard.dk 70 i
Err mx1.adamsgaard.dk 70 i 
    @article{Knudsen2015,	Err	mx1.adamsgaard.dk	70
i-            author = "Knudsen, M. F. and Egholm, D. L. and Jacobsen, B. H.	Err	mx1.adamsgaard.dk	70
i-                and Larsen, N. K. and Jansen, J. D. and Andersen, J. L.	Err	mx1.adamsgaard.dk	70
i-                and Linge, H. C.",	Err	mx1.adamsgaard.dk	70
i-            title = "A multi-nuclide approach to constrain landscape	Err	mx1.adamsgaard.dk	70
i-                evolution and past erosion rates in previously glaciated	Err	mx1.adamsgaard.dk	70
i-                terrains",	Err	mx1.adamsgaard.dk	70
i-            journal = "Quaternary Geochronology",	Err	mx1.adamsgaard.dk	70
i-            volume = "30, Part A",	Err	mx1.adamsgaard.dk	70
i-            number = "",	Err	mx1.adamsgaard.dk	70
i-            pages = "100--113",	Err	mx1.adamsgaard.dk	70
i-            year = "2015",	Err	mx1.adamsgaard.dk	70
i-            issn = "1871-1014",	Err	mx1.adamsgaard.dk	70
i-            doi = "http://dx.doi.org/10.1016/j.quageo.2015.08.004",	Err	mx1.adamsgaard.dk	70
i-        }	Err	mx1.adamsgaard.dk	70
i+        author = "Knudsen, M. F. and Egholm, D. L. and Jacobsen, B. H.	Err	mx1.adamsgaard.dk	70
i+            and Larsen, N. K. and Jansen, J. D. and Andersen, J. L.	Err	mx1.adamsgaard.dk	70
i+            and Linge, H. C.",	Err	mx1.adamsgaard.dk	70
i+        title = "A multi-nuclide approach to constrain landscape	Err	mx1.adamsgaard.dk	70
i+            evolution and past erosion rates in previously glaciated	Err	mx1.adamsgaard.dk	70
i+            terrains",	Err	mx1.adamsgaard.dk	70
i+        journal = "Quaternary Geochronology",	Err	mx1.adamsgaard.dk	70
i+        volume = "30, Part A",	Err	mx1.adamsgaard.dk	70
i+        number = "",	Err	mx1.adamsgaard.dk	70
i+        pages = "100--113",	Err	mx1.adamsgaard.dk	70
i+        year = "2015",	Err	mx1.adamsgaard.dk	70
i+        issn = "1871-1014",	Err	mx1.adamsgaard.dk	70
i+        doi = "http://dx.doi.org/10.1016/j.quageo.2015.08.004",	Err	mx1.adamsgaard.dk	70
i+    }	Err	mx1.adamsgaard.dk	70
i
Err mx1.adamsgaard.dk 70 i
Err mx1.adamsgaard.dk 70 i Err mx1.adamsgaard.dk 70 .