Comparing landscape evolution models with quantitative field data at the millennial time scale in the Belgian loess belt

2011 ◽  
Vol 36 (10) ◽  
pp. 1300-1312 ◽  
Author(s):  
A. J. A. M. Temme ◽  
I. Peeters ◽  
E. Buis ◽  
A. Veldkamp ◽  
G. Govers
Keyword(s):  
Time Scale ◽  
Field Data ◽  
Landscape Evolution ◽  
Millennial Time Scale

Variations and controls of iron oxides and isotope compositions during paddy soil evolution over a millennial time scale

2018 ◽  
Vol 476 ◽  
pp. 340-351 ◽  
Author(s):  
Lai-Ming Huang ◽  
Xiao-Xu Jia ◽  
Gan-Lin Zhang ◽  
Aaron Thompson ◽  
Fang Huang ◽  
...  
Keyword(s):  
Iron Oxides ◽  
Paddy Soil ◽  
Time Scale ◽  
Soil Evolution ◽  
Millennial Time Scale

scholarly journals Easy Volcanic Aerosol (EVA v1.0): An idealized forcing generator for climate simulations

2016 ◽  
Author(s):  
Matthew Toohey ◽  
Bjorn Stevens ◽  
Hauke Schmidt ◽  
Claudia Timmreck
Keyword(s):  
Time Scale ◽  
Climate Models ◽  
Single Scattering ◽  
Stratospheric Aerosol ◽  
Asymmetry Factor ◽  
Volcanic Aerosol ◽  
Climate Simulations ◽  
Simple Scaling ◽  
Millennial Time Scale ◽  
Aerosol Properties

Abstract. The Easy Volcanic Aerosol (EVA) forcing generator produces stratospheric aerosol optical properties as a function of time, latitude, height and wavelength for a given input list of volcanic eruption attributes. EVA is based on a parameterized three-box model of stratospheric transport, and simple scaling relationships used to derive mid-visible (550 nm) aerosol optical depth and aerosol effective radius from stratospheric sulfate mass. Pre-calculated look up tables computed from Mie theory are used to produce wavelength dependent aerosol extinction, single scattering albedo and scattering asymmetry factor values. The structural form of EVA, and the tuning of its parameters, are chosen to produce best agreement with the satellite-based reconstruction of stratospheric aerosol properties following the 1991 Pinatubo eruption, and with prior millennial-time scale forcing reconstructions including the 1815 eruption of Tambora. EVA can be used to produce volcanic forcing for climate models which is based on recent observations and physical understanding, but internally self-consistent over any time-scale of choice. In addition, EVA is constructed so as to allow for easy modification of different aspects of aerosol properties, in order to be used in model experiments to help advance understanding of what aspects of the volcanic aerosol are important for the climate system.

scholarly journals Accelerator Mass Spectrometry at Arizona: Geochronology of the Climatic Record and Connections with the Ocean

2002 ◽  
Vol 2 ◽  
pp. 1579-1593 ◽  
Author(s):  
J.T. Jull ◽  
G.S. Burr ◽  
J.W. Beck ◽  
D.J. Donahue ◽  
D. Biddulph ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Radioactive Waste ◽  
Environmental Conditions ◽  
Accelerator Mass Spectrometry ◽  
Time Scale ◽  
Southern Oscillation ◽  
Waste Dump ◽  
Short Term ◽  
Millennial Time Scale ◽  
Climatic Record

There are many diverse uses of accelerator mass spectrometry (AMS).14C studies at our laboratory include much research related to paleoclimate, with14C as a tracer of past changes in environmental conditions as observed in corals, marine sediments, and many terrestrial records. Terrestrial records can also show the influence of oceanic oscillations, whether they are short term, such as ENSO (El Niño/Southern Oscillation), or on the millennial time scale. In tracer applications, we have developed the use of129I as well as14C as tracers for nuclear pollution studies around radioactive waste dump sites, in collaboration with IAEA. We discuss some applications carried out in Tucson, AZ, for several of these fields and hope to give some idea of the breadth of these studies.

Postglacial evolution of a formerly glaciated valley: Reconstructing sediment supply, fan building, and confluence effects at the millennial time scale

2018 ◽  
Vol 130 (9-10) ◽  
pp. 1457-1473 ◽  
Author(s):  
Francesco Brardinoni ◽  
Vincenzo Picotti ◽  
Stefano Maraio ◽  
Pier Paolo Bruno ◽  
Maurizio Cucato ◽  
...  
Keyword(s):  
Time Scale ◽  
Sediment Supply ◽  
Millennial Time Scale ◽  
Glaciated Valley

East Asia winter monsoon variations on a millennial time-scale before the last glacial-interglacial cycle

1999 ◽  
Vol 14 (2) ◽  
pp. 101-110 ◽  
Author(s):  
Huayu Lu ◽  
Ko Van Huissteden ◽  
Zhisheng An ◽  
Govert Nugteren ◽  
Jef Vandenberghe
Keyword(s):  
East Asia ◽  
Time Scale ◽  
Winter Monsoon ◽  
Last Glacial ◽  
Millennial Time Scale ◽  
The Last Glacial

Evolution of the Australian landscape

2001 ◽  
Vol 52 (1) ◽  
pp. 13 ◽  
Author(s):  
C. D. Ollier
Keyword(s):  
Inorganic Chemistry ◽  
Significant Role ◽  
Time Scale ◽  
Landscape Evolution ◽  
Biological Evolution ◽  
Lateral Movement ◽  
Weathered Rock ◽  
The Past ◽  
Global Tectonics ◽  
Natural Laboratory

Landscape evolution of Australia is on the same time scale as global tectonics and biological evolution. In places, actual landforms and deep weathering products are hundreds of millions of years old. Much of Australia has a landscape resulting from stripping of weathered rock after an earlier period of very deep weathering. Other regions have sequential landforms that provide a natural laboratory where we can work out the biogeochemistry of the past. Landforms and regolith reveal the long evolution of groundwater in Australia. Lateral movement of groundwater is of paramount importance. The effects of past climates are stored in the landscape. They show that the present is not the key to the past, and former environments must be worked out from consistent internal evidence rather than the application of models based on present-day conditions. Inorganic chemistry alone is inadequate to explain many earth materials, and biology, especially microbiology, has a very significant role. Recent and present-day processes also affect the landscape, and it cannot be assumed that because the landscape and regolith are old the soils are old. Many regions have a complex regolith cover that shows modern processes working on inherited materials.

scholarly journals Assessment of F200 fluence for major solar energetic particle events on the multi-millennial time scale

2016 ◽  
Author(s):  
Ilya Usoskin ◽  
Gennady Kovaltsov ◽  
Edward Cliver ◽  
William F. Dietrich ◽  
Allan Tylka
Keyword(s):  
Time Scale ◽  
Energetic Particle ◽  
Solar Energetic Particle ◽  
Solar Energetic Particle Events ◽  
Millennial Time Scale

scholarly journals Spatio-temporal dynamics of sediment transfer systems in landslide-prone alpine catchments

2019 ◽  
Author(s):  
François Clapuyt ◽  
Veerle Vanacker ◽  
Fritz Schlunegger ◽  
Marcus Christl ◽  
Kristof Van Oost
Keyword(s):  
Time Scales ◽  
Time Scale ◽  
Landscape Evolution ◽  
Sediment Budget ◽  
Spatial And Temporal Scales ◽  
Sediment Fluxes ◽  
Downstream Distance ◽  
Denudation Rates ◽  
Decadal Scale

Abstract. Tectonic and geomorphic processes drive landscape evolution over different spatial and temporal scales. In mountainous environments, river incision sets the pace of landscape evolution, and hillslopes respond to channel incision by e.g. gully retreat, bank erosion and landslides. Sediment produced during stochastic landslide events leads to mobilisation of soil and regolith on the slopes that can later be transported by gravity and water to the river network. Quantifying sediment storage and conveyance requires an integrated approach accounting for different space and time scales. To better understand mechanisms and spatial and temporal scales of geomorphic connectivity in mountainous environments, we characterised the sediment cascade of the Entle River catchment located in the foothills of the Central Swiss Alps. We quantified sediment fluxes over annual, decadal and millennial time scales using respectively UAV-SfM techniques, classic photogrammetry and in situ produced cosmogenic radionuclides. At the annual scale (2013–2015), the sediment budget of the Schimbrig earthflow is roughly in equilibrium, despite the fact that we measured intense sediment redistribution on the hillslopes. At the decadal scale (1962–1998), Schwab et al. (2008) reported episodes of sediment export that were not directly related to increased geomorphic activity on the hillslopes. At the millennial scale, catchment-wide denudation rates show a positive relationship with downstream distance or drainage area, when ignoring landslide-affected catchments. The latter are characterised by a negative relationship between denudation rates and downstream distance, along with high variability in denudation rates. The high denudation rates that we measured in the earthflow-affected Schimbrig catchment are illustrative for its high rates of geomorphic activity in comparison to adjacent areas. Our data show that the elevated denudation rates of the landslide-affected catchments are not necessary traceable when analyzing long-term sediment fluxes of the wider geographic area, as the landslide-affected catchments are often only a small fraction of the total catchment. The multi-temporal assessment of sediment fluxes indicates that (1) landslides can provide local sediment pulses, and mobilise material that becomes available for further mobilisation and transport when hillslopes and channels are connected. (2) Connection and disconnection cycles occur at decadal time scale. (3) Phases of high geomorphic activity at the catchment scale are episodic over thousands of years. Consequently, one single landslide has not necessarily an impact on the long-term sediment budget of first-order catchments. Rather, it is the cumulated effect of multiple landslides which are intermittently connected to the channel network at the decadal scale that may regulate sediment fluxes at the regional scale over the millennial time scale.

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