Gerald RaabDalhousie University | Dal · Department of Earth and Environmental Sciences
Gerald Raab
PhD (Dr. sc. nat.)
Being a "Cosmonaut" :P.
About
46
Publications
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182
Citations
Citations since 2017
Introduction
For more information, visit my website @
www.geraldraab.com
Publications
Publications (46)
Landscape evolution is driven by tectonics, climate and surface denudation. In New Zealand, tectonics and steep climatic gradients cause a dynamic landscape with intense chemical weathering, rapid soil formation, and high soil losses. In this study, soil, and elemental redistribution along two adjacent hillslopes in East Otago, New Zealand, having...
Few data are available on how soil erosion rates compare between surfaces of different ages because short-term processes often overprint the longer-term erosion signal. This study investigated the soil dynamics among two end-member sites, a formerly glaciated ('young', maximum glacial extent at 22–30 ka BP) and a non-glaciated ('old') area at the S...
Landscapes are subjected to surface denudation during their complex and non-linear evolution. In order to quantify the in situ surface lowering and, thus, denudation or soil erosion rates, new, multi-millennia archives are needed and must be rigorously tested. Large residual rocks, tors, are the basis for the Tor Exhumation Approach. Here we presen...
In Europe, a high soil erosion risk is modelled for the Mediterranean area such as the Iberian Peninsula (e.g., EEA, 2009), while actual field data often lacks behind. Here we present the first 239+240Pu soil erosion results (last ~60 years) in the UNESCO Geopark Estrela, Portugal. We investigated soils in a former vastly glaciated and a non-glacia...
How soil erosion rates evolved over the last about 100 kyr and how they relate to environmental and climate variability is largely unknown. This is due to a lack of suitable archives that help to trace this evolution. We determined in-situ cosmogenic 10Be along vertical landforms (tors, boulders and scarps) on the Sila Massif to unravel their local...
Few data are available on how soil erosion rates compare between surfaces of different ages because short-term processes often overprint the longer-term erosion signal. This study investigated the soil dynamics among two end-member sites, a formerly glaciated ('young', maximum glacial extent at 22–30 ka BP) and a non-glaciated ('old') area at the S...
Landscapes are subjected to surface denudation during their complex and non-linear evolution. Yet, tectonic uplift and surface denudation rates are mostly averaged over multi-millennia. In result, temporal fluctuations are often unknown or even neglected. The recent development of the tor exhumation approach (TEA) focuses on the quantification of t...
Landscapes are subjected to changing environmental conditions. Yet, capturing the surface denudation variations over geological timescales remains challenging due to the lack of suitable archives. Therefore, the Tor Exhumation Approach (TEA) was developed in recent years (Raab, 2019), unlocking a new in-situ archive with continuous surface denudati...
New Zealand is characterised by high uplift rates and strong erosion. Currently only a few studies have investigated the local soil redistribution and degradation processes at the largest semi-arid area in New Zealand. Here we present the elemental redistributions results of our comparative study between small hills at an intraterrain valley and an...
Talk @
14th International Young Geomorphologists Meeting
Digital Edition 29th-30th, 2020
The Tor Exhumation Approach (TEA) traditionally uses large residual granitic landforms as indicators for surface lowering over time of their surrounding landscape. This study challenged the broad applicability of this approach by using large metamorphic residual landforms instead of the traditional plutonic rock formations. We applied in-situ cosmo...
Landscapes and soils are subjected to changing environmental conditions, resulting in a non-linear evolution over time. Capturing the variations of surface denudation and soil erosion over geological timescales remains challenging due to the lack of suitable archives. Common denudation studies using cosmogenic nuclides and catchment-wide approaches...
How soil erosion rates evolved over the last about 100 ka and how they relate to environmental and climate variability is largely unknown. This is due to a lack of suitable archives that help to trace this evolution. We determined in situ cosmogenic beryllium‐10 (¹⁰Be) along vertical landforms (tors, boulders and scarps) on the Sila Massif to unrav...
The importance of gradual erosion relative to landsliding depends predominantly on the slope angle. One factor of critical influence in landsliding along with slope angle and slope shape is the soil depth. Understanding soil depth development on steep topography is fundamental for understanding and predicting the occurrence of landsliding at thresh...
In this short course we discussed the basics of scientific visualization and summarized some key questions in this infographic.
Granitic landforms such as boulders and tors adorn the upland of several landscapes worldwide. The rate of emergence of these tors from surface could be an indicator of surface lowering over time. Therefore, tors might be a good archive of soil erosion rates over time. We applied in-situ cosmogenic nuclide techniques (10Be) along vertical landforms...
Recent modeling and comparison with field results showed that soil formation by chemical weathering, from bedrock or unconsolidated material, is limited largely by solute transport. Chemical weathering rates are proportional to solute velocities. Nonreactive solute transport described by non-Gaussian transport theory appears compatible with soil fo...
Earth surfaces and soils are shaped in complex and non-linear ways over thousands of years. Many studies have tried estimating average erosion and denudation rates over different time periods, neglecting the temporal discontinuities of these processes. The often-used catchment-wide approach does not differentiate between soil erosion from erosion a...
Soil chronosequences have been widely used to quantify soil formation and weathering rates, but little attention has been paid to determine soil redistribution rates (erosion and deposition) and the stabilisation of moraines over time. We therefore selected a sequence of moraines in the Wind River Range (WRR-Central Rocky Mountains) to study these...
Landscapes and soils evolve in non‐linear ways over millennia. Current knowledge is incomplete as only average denudation (or erosion) rates are normally estimated, neglecting the temporal discontinuities of these processes. The determination of regressive and progressive phases of soil evolution is important to our understanding of how soils and l...
Data from soil chronosequences have been widely used to quantify soil formation and weathering rates, but are less used to determine erosion rates and the stabilisation of moraines over time. We hypothesise that soil erosion rates on moraine hillslopes decrease over time as soils evolve and slopes stabilise. We selected a sequence of moraines in th...
Landscapes and soils are shaped by changing environmental conditions and evolve in non-linear and complex ways. Many studies have tried to derive a chronology of process rates by comparing erosion rates over different time periods. However, capturing the full variability over a continues time-line remains a key challenge, because the often used cat...
Little is known about the extent of glaciers and dynamics of the landscape in south-eastern Russian Altai. The effects of climate-induced fluctuations of the glaciers and the upper treeline of the Mongun-Taiga mountain massif were, therefore, reconstructed on the basis of in-situ, multiannual observations, geomorphic mapping, radiocarbon and surfac...
Mediterranean soils are an important key to understanding past volcanic events and landscape evolution. The influence and timing of Quaternary volcanic events on soils, however, remains still poorly understood in southern Italy. We used a multi-method approach to explore the origin and age of volcanic deposits (soils) in Sicily and Calabria. By com...
Erosion distinctly shapes earth's surface and therefore influences landscape and, in particular, also soils. The evolution of landscapes and soils are known to evolve in discontinuous ways over thousands of years. Several studies have tried to compare erosion rates over different time periods, thereby trying to derive a chronology of process rates....
Only scarce information is available on how organic C is incorporated into the soil during the decay and how (micro) climate influences this process. Therefore, we investigated the effect of exposure and elevation on the organic litter decomposition and C-stabilisation in acidic soils of an Alpine environment. An experiment with artificially ¹³C la...
Diatomite is well known to remove particulate matter for a broad range of applications due to diatom skeleton structures. Hydrothermally treated diatomite has been demonstrated to be a feasible pathway to produce advanced materials for the removal of aqueous heavy metal ions. However, single-synthesis routes to obtain altered diatomite for simultan...
Questions
Question (1)
I am in the need of data (d18O, d13C, T, SST, etc.) that is available in a readable format (e.g. .xls, .csv, .txt) of varies ODP campaigns (e.g. ODP 977, 653, 963, 964 etc.).
I would appreciate if you could include the data files already in your answere.
Best regards
Gerald
Projects
Projects (9)
Dear all,
After many years of success, we will again organize a "Crowd-solving Problems in Earth Sciences" session at EGU2022. To host another successful session in 2022, we need some problems to solve! Since EGU will take place in May as a hybrid meeting, we will come together in Vienna AND online for our session to start crowd-solving these problems!
What can you contribute?
In Earth Science research, we face a diverse range of challenges for which solutions are not always straight forward. Do you have any challenges that you think other Geoscientists might face? If you are planning to attend the EGU2022 and have any challenges you'd like to discuss, please submit your problem/challenge via this form: https://forms.gle/tLrDUrTv9Ephw7cg9. These may be methodological, logistical, or work-life balance related. As an example, problems from vEGU2021 included: ‘Do we need ground-truthing?’ and ‘What is significant in our statistics?’ If you need some inspiration, find out what we got up last year: https://blogs.egu.eu/geolog/2021/07/02/crowd-solutions-to-challenges-in-earth-sciences/
What do we offer?
In this crowd-solving session we offer a safe and non-hierarchical format to discuss your challenges with fellow Earth Scientists and come to a solution together. This session will be offered as a hybrid session and can be attended online and on-site. All the convenors are early career scientists, so we particularly encourage other early career scientists to join us at this short course! It’s a great opportunity to meet other (early career) researchers!
Important deadlines:
Deadline problem submission: April, 15th
EGU22 in Vienna and hybrid: May, 23rd to 27th
Hopefully see you at the EGU2022!
Renee van Dongen, Erin Harvey, Sam Woor, Gerald Raab, Hannah Gies, Anne Voigtländer and Bastian Grimm
The project focuses on glacial erratics, thus deposited allochthonous material that differs from the rock type of its current resting area on Disko Island in Western Greenland. There, granitic boulders of the Precambrian basement rest on the Palaogene island basalt. The goal is to identify the time of deposition and the source of these erratic boulders. The mapping and dating of these erratics will provide important constraints in the thinning and timing of deglaciation of the former ice sheet of Disko Bugs and new constraints on ice cape and ice sheet thickness during the last and potentially previous ice age glaciation.
The project "Determining Relief Evolution in the Alps with Muon Paleotopometry", or "DREAM-P" intends to quantify relief formation and responsible denudation drivers in the alps using muon paleotopometry (MPT). Understanding of relief development is important because relief controls regional and global climate, sediment fluxes to basins and oceans and geohazard frequency. MPT is a newly conceived method still in development, therefore the project is executed in close collaboration with Dalhousie University (Halifax, Canada), SwissTopo and the Grimsel Test Site (Switzerland).
