Seiteninhalt:
Dr. David Heslop
Name: | Herr Dr. David Heslop | |
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Abteilung: | Marine Geophysik | |
Funktionen: | wissenschaftlicher Assistent | |
Telefon: | 0421 218 - 65442 | |
Fax: | 0421 218 - 7008 | |
E-Mail: |
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Current Research
I am currently part of a team working on the DAMOCLES project (Detecting Holocene changes in the Atlantic Meridional Overturning Circulation: Integration of Proxy Data and Climate Simulations), which is part of the DFG SSP Programme “INTERDYNAMIK”. My work involves using the University of Victoria Earth System Climate Model (Uvic ESCM), to investigate the driving of the Atlantic Multidecadal Oscillation and asses its signature within ocean sediment archives. As this work progresses I will be posting examples of the results with discussions of their implications.
Additional Research
My other research interests are really quite varied, but my publication list should give you a flavour of what I do. Most of my previous work has been in rock magnetism, but I have also spent time working on problems in time series analysis and statistics. One of the problems I have become interested in is understanding natural mixtures and finding mathematical methods which help us to break up mixed signals into their component parts in order that we can understand them better. Below are brief introductions to some of the research problems I have worked on.
NEWS: The Software package "DRS-Unmixer 1.0" is now available for calculating linear mixture models from diffuse reflectance data. To download the software visit the link "Using non-negative matrix factorization in the unmixing of diffuse reflectance spectra".
NEWS: The Software package "IRM-Unmixer 1.0" is now available for calculating linear mixture models from isothermal remanent magnetization data. To download the software visit the link "Unmixing magnetic remanence curves without a priori knowledge".
- Using non-negative matrix factorization in the unmixing of diffuse reflectance spectra.
- A wavelet investigation of possible orbital influences on past geomagnetic field intensity
- Unmixing magnetic remanence curves without a priori knowledge
- A Monte-Carlo model of thermally activated single-domain particles
- Selected Reprints
Publications 2011
| J.A. Collins, E. Schefuß, D. Heslop, S. Mulitza, M. Prange, M. Zabel, R. Tjallingii, T.M. Dokken, E. Huang, A. Mackensen, M. Schulz, J. Tian, M. Zarriess, G. Wefer. Interhemispheric symmetry of the tropical African rainbelt over the past 23,000 years. Nat. Geosci. 4. |
| D. Heslop, S. De Schepper, U. Proske. Diagnosing the uncertainty of taxa relative abundances derived from count data. Marine Micropaleontology (Accepted). |
| D. Heslop, A. Paul. Can oceanic paleothermometers reconstruct the Atlantic Multidecadal Oscillation? Climate of the Past (Accepted). |
| D. Heslop, A. Paul. Fingerprinting of the Atlantic meridional overturning circulation in climate models to aid in the design of proxy investigations. Climate Dynamics (in review). |
| A.R. Muxworthy, D. Heslop. A Preisach method to estimate absolute paleofield intensity under the constraint of using only isothermal measurements: 1. theoretical framework. Journal of Geophysical Research (in press). |
| A.R. Muxworthy, D. Heslop, G.A. Paterson et al. A Preisach method to estimate absolute paleofield intensity under the constraint of using only isothermal measurements: 2. experimental testing. Journal of Geophysical Research (in press). |
Publications 2010
| G. A. Paterson, D. Heslop and A. R. Muxworthy. Deriving confidence in palaeointensity estimates. Geochem. Geophys. Geosyst. 11, Q07Z18, doi:10.1029/2010GC003071. |
| S. Mulitza, D. Heslop, D. Pittauerova, H. W. Fischer, I. Meyer, J.-B. Stuut, M. Zabel, G. Mollenhauer, J. A. Collins, H. Kuhnert and M. Schulz. Increase in African dust flux at the onset of commercial agriculture in the Sahel region. Nature 466, 226-228. doi:10.1038/nature09213. |
| J. Nizou, T.J.J. Hanebuth, D. Heslop, T. Schwenk, L. Palamenghi, J.-B. Stuut and R. Henrich. The Senegal River mud belt: A high-resolution archive of paleoclimatic change and coastal evolution. Mar. Geol. 278, 150-164. |
| A. Bamberg, Y. Rosenthal, A. Paul, D. Heslop, S. Mulitza, C. Ruhlemann and M. Schulz. Reduced North Atlantic Central Water formation in response to early Holocene ice-sheet melting. Geophys. Res. Letts. 37, L17705, doi:10.1029/2010GL043878. |
| C. M. Köhler, W. Krijgsman, D. J. J. van Hinsbergen, D. Heslop and G. Dupont-Nivet. Concurrent tectonic and climatic changes recorded in upper Tortonian sediments from the Eastern Mediterranean. Terra Nova 22(1) 52-63. doi:10.1111/j.1365-3121.2009.00916.x |
| S. Rauch, B. Peucker-Ehrenbrink, M. Kylander, D. Weiss, A. Martínez-Cortizas, D. Heslop, C. Olid, T. Mighall, H. Hemond (2010). Anthropogenic forcings on the surficial osmium cycle. Environ. Sci. Tech. 44(3), 881-887, doi:10.1021/es901887f. |
| C. M. Köhler, D. Heslop, W. Krijgsman and M. J. Dekkers (2010). Late Miocene paleoenvironmental changes in North Africa and the Mediterranean recorded by geochemical proxies (Monte Gibliscemi section, Sicily). Palaeogeogr. Palaeoclimatol. Palaeoecol. 285, 66-73. |
Publications 2009
| D. Heslop (2009). Statistical analysis of the rock magnetic S-ratio. Geophys. J. Int. 178(1), 159-161. |
| A.R. Muxworthy, D. Heslop and D.M. Michalk (2009). Thermal fluctuation fields in basalts. Earth Planets Space, 61, 111-117. |
| Z. Gong, M.J. Dekkers, D. Heslop, T.A.T. Mullender (2009). End-member modelling of isothermal remanent magnetization (IRM) acquisition curves: a novel approach to diagnose remagnetization. Geophys. J. Int. 178(2), 693-701. |
| A. C. Itambi, T. von Dobeneck, S. Mulitza, T. Bickert and D. Heslop (2009) Millennial-scale North West African droughts relates to H-Events and D-O cycles: Evidence from marine sediments from off-shore Senegal. Paleoceanography, 24, PA1205, doi:10.1029/2007/PA001570. |
| C. Franke, Y. Fu, D. Heslop, T. von Dobeneck, T., (2009). Data report: natural remanent magnetization of IODP Holes U1319A, U1320A, U1322B, and U1324B and magnetic carrier identification by scanning electron microscopy. In Flemings, P.B., Behrmann, J.H., John, C.M., and the Expedition 308 Scientists, Proc. IODP, 308: College Station, TX (Integrated Ocean Drilling Program Management International, Inc.). doi:10.2204/iodp.proc.308.209.2009 |
Publications 2008
| P. D. Clift, K. V. Hodges, D. Heslop, R. Hannigan, H. V. Long and G. Calves (2008). Correlation of Himalayan exhumation rates and Asian monsoon intensity. Nature Geoscience, doi:10.1038/ngeo351. |
| C.M. Köhler, D. Heslop, M.J. Dekkers, W. Krijgsman, .J.J. van Hinsbergen and T. von Dobeneck (2008). Tracking provenance change during the late Miocene in the Eastern Mediterranean using geochemical and environmental magnetic parameters Geochem. Geophys. Geosyst. doi:10.1029/2008GC002127. |
| Y. Fu, T. von Dobeneck, C. Franke, D. Heslop and S. Kasten (2008). Rock magnetic identification and geochemical process models of greigite ormation in Quaternary marine sediments from the Gulf of Mexico (IODP Hole U1319A). Earth and Planetary Science Letters, 275(3-4), 233-245. |
| U. Proske, D. Heslop and T. J. J. Hanebuth (2008). Salt production in pre-Funan Vietnam: archaeomagnetic reorientation of briquetage fragments. Journal of Archaeological Science, 36, 84-89. |
Publications 2007
| Heslop, D. (2007). Are hydrodynamic shape effects important when modelling the formation of depositional remanent magnetization? Geophys. J. Int. 171, 1029-1035 (RCOM0528). |
| Heslop, D. (2007). A wavelet investigation of possible orbital influences on past geomagnetic field intensity. Geochem. Geophys. Geosyst. Vol. 8, Q03003, DOI-10.1029/2006GC001498. |
| Heslop, D. and Dillon, M. (2007). Unmixing magnetic remanence curves without a priori knowledge. Geophys. J. Int. 170(2), 556-566 (RCOM0487). |
| Heslop, D. von Dobeneck, T. and Höcker, M. (2007). Using non-negative matrix factorization in the unmixing of diffuse reflectance spectra. Mar. Geol., 241, 63-78 (RCOM0488). |
Publications 2006
| Heslop, D. Witt, A. Kleiner, T. and Fabian, K. (2006). The role of magnetostatic interactions in sediment suspensions. Geophy. J. Int., 165 (3). 775-785. |
Publications 2005
| Heslop, D. (2005). A Monte Carlo investigation of the representation of thermally activated single-domain particles within the Day plot. Studia Geophysica Geodetica, 49, 163-176. |
| Heslop, D. and Muxworthy, A.R. (2005). Aspects of calculating First-Order Reversal Curve distributions. J. Magn. Magn. Mater. 288, 155-167. |
| Muxworthy, A.R. King, J. and Heslop, D. (2005). Assessing the ability of First-order-reversal-curve (FORC)diagrams to unravel complex magnetic signals. J. Geophys. Res. 110 (B1): Art. No. B01105. |
Publications 2004
| Heslop, D. McIntosh, G. and Dekkers M.J. (2004). Using time- and temperature-dependent Preisach models to investigate the limitations of modelling isothermal remanent magnetization acquisition curves with cumulative log Gaussian functions. Geophys. J. Int., 157, 55-63. |
| Muxworthy, A.R. Heslop, D. and Williams, W. (2004). Influence of magnetostatic interactions on First-Order Reversal Curve (FORC) diagrams: a micromagnetic approach. Geophys. J. Int., 158, 888-897. |
Publications 2002
| Heslop D. and Dekkers M.J. (2002). Spectral analysis of unevenly spaced climatic time series using CLEAN: signal recovery and derivation of significance levels using a Monte Carlo simulation, Phys. Earth Planet. Inter., 130, 103-116. |
| Heslop, D., Dekkers, M.J., Kruiver, P.P. and Van Oorschot, I.H.M. (2002). Analysis of isothermal remanent magnetisation acquisition curves using the expectation-maximisation algorithm. Geophys. J. Int., 148, 58-64. |
| Heslop, D., Dekkers, M.J. and Langereis, C.G. (2002). Timing and structure of the Mid-Pleistocene Transition: records from the loess deposits of Northern China. Palaeogeogr. Palaeoclimatol. Palaeoecol., 105, 133-143. |
Publications 2001
| Kruiver, P.P., Dekkers, M.J., and Heslop, D. (2001). Quantification of magnetic coercivity components by the analysis of acquisition curves of isothermal remanent magnetisation, Earth Planet. Sci. Lett., 189, 269-276. |
Publications 2000
| Heslop, D., Langereis, C.G. and Dekkers, M.J. (2000). A new astronomical time scale for the loess deposits of Northern China, Earth Planet. Sci. Lett., 184, 125-139. |
| Partridge, T.C., Latham, A. and Heslop, D. (2000). Magnetostratigraphy of Makapansgat, Sterkfontein, Taung and Swartkrans. In: The Cenozoic of southern Africa, 126-129. |
| Partridge, T.C., Shaw, J. and Heslop, D. (2000). Note on recent magnetostratigraphic analysis in Member 2 of the Sterkfontein formation. In: The Cenozoic of southern Africa, 129-130. |
Publications 1999
| Heslop, D., Shaw, J., Bloemendal, J. et al. (1999). Sub-Millenial scale variations in East Asian monsoon systems recorded by dust deposits from North-Western Chinese Loess Plateau, Phys. Chem. Earth, A, 24(9), 785-792. |
| Partridge, T.C., Shaw, J., Heslop, D., Clarke, R.J. (1999). The new hominid skeleton from Sterkfontein, South Africa: age and preliminary assessment. J. Quat. Sci., 14(4),293-298. |
Conference Contributions (since 2002)
| Muxworthy, A.R. & Heslop, D. (2008). Interpreting first-order reversal curve (FORC) diagrams; what do they tell us? AGU Spring. |
| Muxworthy, A.R. & Heslop, D. (2008).Toward a new non-heating method of determining absolute paleointensities. AGU Fall. |
| Muxworthy, A.R. & Heslop, D. (2008). Interpreting first-order reversal curve (FORC) diagrams; what do they tell us? 11th Castle Meeting. |
| Heslop, D. (2007). Proxy information derived from sediment colour. Annual Meeting of the Geologische Vereinigung, Bremen. |
| Heslop, D. (2007). A wavelet investigation of possible orbital influences on past geomagnetic field intensity. EGU General Assembly, Vienna. |
| Heslop, D. & Dillon, M. (2007). Unmixing magnetic remanence curves without a priori knowledge. EGU General Assembly, Vienna. |
| Franke, C., Fu, Y., Heslop, D., Kasten, S., Gilhooly, W., Jiang, S.-Y. & von Dobeneck, T. (2007). Time constraints, magnetic mineralogy and geochemistry for overpressured sediments from the continental slope in the northwestern Gulf of Mexico (IODP Exp. 308). EGU General Assembly, Vienna. |
| Muxworthy, A. & Heslop, D. (2007). Revisiting hysteresis quantification and representation. EGU General Assembly, Vienna. |
| Fu, Y., Heslop, D., Franke, C., Frederichs, T., Flemmings, P.B., John, C., Behrmann, J. & von Dobeneck, T. (2006). A paleomagnetic and rock magnetic study of the stratigraphic evolution of the Brazos Trinity Basin #4, Gulf of Mexico. EGU General Assembly, Vienna. |
| Fu, Y., Heslop, D., Franke, C. Frederichs, T. Flemings, P.B., John, C., Behrmann, J. & von Dobeneck, T. (2006). Paleo- and rock magnetic investigation of Brazos Trinity Basin 4, Gulf of Mexico – IODP, Leg 308, Site U1319A and U1320A. DGG General Assembly, Bremen. |
| Heslop, D. (2006). Modelling magnetic particle orientation during sedimentation through a still water column. DGG General Assembly, Bremen. |
| Heslop, D., Höcker, M., Itambi, C. & Köhler, C. (2006). A new method to unmix sediment colour data, with specific reference to hematite and goethite abundances. EGU General Assembly, Vienna. |
| Heslop, D. & Muxworthy, A.R. (2006). Selecting suitable smoothing factors for First-Order Reversal Curve distributions. EGU General Assembly, Vienna. |
| Höcker, M., Köhler, C.M., Heslop, D., von Dobeneck, T., Krijgsman, W. & Langereis, C.G. (2006). North African palaeomonsoon variability: reconstructions of Saharan dust supply to the Mediterranean Sea based on records of aeolian hematite and goethite. EGU General Assembly, Vienna. |
| Höcker, M., Köhler, C.M., Heslop, D., von Dobeneck, T. & Langereis, C.G. (2006) Neogene monsoon variability over North Africa: Saharan dust supply to the Mediterranean Sea reconstructed by rock magnetic, color spectrometric and voltammetric proxy records based on hematite and goethite content. DGG General Assembly, Bremen. |
| Köhler, C.M., Höcker, M., Heslop, D., von Dobeneck, T. and Krijgsman, W. (2006). Late Miocene climate reconstruction based on the Mediterranean Metochia section using hematite and goethite proxies. DGG General Assembly, Bremen. |
| Forté, S., von Dobeneck, T., Hamer, K., Heslop, D., Hilgenfeldt, C., Müller, H., Steinbach, A. & Fu, Y. (2005). An environmental magnetic survey of the Schlei inlet, Baltic Sea. EGU General Assembly, Vienna. |
| Franke, C., Heslop, D., Fu, Y., Flemings, P., John, C. and Behrmann, J. (2005). Towards a Precise Age Model of IODP Holes U1319B and U1320B (Leg 308, Brazos-Trinity Basin IV, Gulf of Mexico) with Paleo- and Rock Magnetic Methods. AGU Fall, San Francisco. |
| Heslop, D. & Witt, A. (2005). Modelling sedimentary remanent magnetizations using the discrete element method. EGU General Assembly, Vienna. |
| Heslop, D. & Witt, A. (2005). Modelling inclination shallowing using the discrete element method. DFG SPP Workshop, Bremen. |
| Heslop, D., Witt, A., von Dobeneck, T., Huhn, K., Fabian, K. & Bleil, U. (2004). Discrete element modeling of post depositional remanent magnetization acquisition: first results. AGU Fall, San Francisco. |
| Oda, H., Dekkers M.J., Langereis, C.G., Lourens, L. & Heslop, D. (2004). A paleomagnetic record of the last 640 kyr from an eastern Mediterranean piston core and a review of geomagnetic excursions in the Brunhes. AGU Fall, San Francisco. |
| Witt, A., Heslop, D., von Dobeneck, T., Huhn, K., Fabian, K. & Bleil, U. (2004). Discrete element modeling of post-depositional remanent magnetization acquisition: numerical principles. AGU Fall, San Francisco. |
| Witt, A., von Dobeneck, T., Heslop, D., Huhn, K., Fabian, K. & Bleil, U. (2004). Discrete element modelling of post-depositional remanent magnetization acquisition. 9th Castle Meeting, Javorina. |
| Heslop, D., McIntosh, G. & Dekkers, M.J. (2003). The influence of initial state, interaction, and thermal relaxation on isothermal remanent magnetisation curves and models. International Union of Geodesy and Geophysics XXIII, Sapporo. |
| Heslop, D., McIntosh, G. & Dekkers, M.J. (2003). Using time and temperature dependant Preisach models to investigate the limitations of modelling isothermal remanent magnetisation curves with cumulative log-Gaussian functions. EGS-AGU-EUG Joint Assembly, Nice. |
| McIntosh, G., Heslop, D., Dekkers, M.J. & Osete, M.L. (2003). Using direct current demagnetisation curves to characterise thermal alteration. EGS-AGU-EUG Joint Assembly, Nice. |
| Muxworthy, A.R., King, J.G., Heslop, D. & Williams, W. (2003). Unravelling magnetic mixtures using first-order reversal curve (FORC) diagrams: linear additivity and interaction effects. AGU Fall, San Francisco. |
| Heslop, D. (2002). Modelling the effects of magnetic interactions on IRM curves. MagNet Workshop, Utrecht. |
| Heslop, D., McIntosh, G. & Dekkers, M.J. (2002). Investigating deviations from log-normality in IRM acquisition curves. INGV Workshop, Erice. |