Deciphering the Incipient Phases of Ice–Mineral Interactions as a Precursor of Physical Weathering

2021 ◽  
Author(s):  
Rebecca A. Lybrand ◽  
Daniel P. Veghte ◽  
Swarup China ◽  
Dragos G. Zaharescu ◽  
Christopher R. Anderton ◽  
...  
Keyword(s):  
Physical Weathering

scholarly journals On the Thermal Stresses Due to Weathering in Natural Stones

2021 ◽  
Vol 11 (3) ◽  
pp. 1188
Author(s):  
William Hideki Ito ◽  
Talita Scussiato ◽  
Federico Vagnon ◽  
Anna Maria Ferrero ◽  
Maria Rita Migliazza ◽  
...  
Keyword(s):  
Building Materials ◽  
Thermal Stresses ◽  
Central Italy ◽  
Theory Of Elasticity ◽  
International Standards ◽  
Natural Material ◽  
Physical Weathering ◽  
Mechanism Of Degradation ◽  
Ancient Times ◽  
Natural Stones

Natural weathering is known as one of the key mechanisms causing degradation in building materials. Great efforts have been made to develop new materials and new processes for protecting those that already exist. Natural stones are an example of a natural material that has been extensively used for building construction since ancient times. In addition, they fit durability, aesthetic, and mechanical requirements. Thus, they still have great importance in the construction business nowadays. Though chemical interactions in natural stones, such as oxidation or hydrolyses, have been widely studied, in the last few decades, the physical weathering due to daily temperature variations has begun to be considered as a key mechanism of degradation and has been incorporated in international standards. This process is particularly important in calcitic marble slabs, where it can cause extensive damages to facades. Consequently, there are restrictive rules for the use of marble as an external coating material in many countries. In this paper, the thermal stresses induced by daily variations in temperature are calculated using geographic and meteorological information. The concept of sol-air temperature is used to estimate the temperatures of the hidden and exposed surfaces of a slab, and Fourier’s law and the theory of elasticity are used to calculate the temperature and stress distribution, respectively. The proposed methodology allows for a detailed reconstruction of the stress induced inside marble slabs using parameters commonly acquired in meteorological stations as input data. The developed methodology was validated by comparing in-situ measurements of the temperature of a building in Pescara (Central Italy). A good correlation between the theoretical and real temperatures was found; in particular, the peak tensile stresses inside the slabs were estimated at 75 kPa.

The Distribution Regularity of Geohazard in the Dry-Hot Valley of Jinsha River: Case Study in Derong County

2012 ◽  
Vol 518-523 ◽  
pp. 5754-5759
Author(s):  
Dong Jian Xue ◽  
Zheng Wei He ◽  
Xiang Dong Zheng
Keyword(s):  
Economic Development ◽  
Tectonic Activity ◽  
Human Engineering ◽  
Monsoon Climate ◽  
Jinsha River ◽  
Physical Weathering ◽  
Geological Conditions ◽  
Vertical Zone ◽  
Landslide Debris

Derong County is located in Ganzi Tibetan Autonomous Prefecture in southern part of Sichuan Province, in the upper of the Jinsha River, where there is a subtropical plateau monsoon climate, abundant sunshine, and large amount of evaporation, so it is a typical dry-hot valleys region. Derong County is the area of more ups and downs in the terrain, deep valleys, steep mountains, complex geological conditions, intense tectonic activity, various climate types, and has obvious vertical zone effect by temperature, serious physical weathering of rock, and landslide, debris flow, collapse and other geohazards are easily induced under the influence of rainfall and human engineering activities. These geohazards have brought serious harm to the people's lives and property, and have a great impact on the socio-economic development. Through the analysis of geohazards in the study area to investigate its distribution and development trends, this paper provide a basis for geohazard prevention and economic development.

Physical Weathering

1970 ◽  
pp. 81-88
Author(s):  
Dorothy Carroll
Keyword(s):  
Physical Weathering

scholarly journals Current glacier recession causes significant rockfall increase: The immediate paraglacial response of deglaciating cirque walls

2020 ◽  
Author(s):  
Ingo Hartmeyer ◽  
Robert Delleske ◽  
Markus Keuschnig ◽  
Michael Krautblatter ◽  
Andreas Lang ◽  
...  
Keyword(s):  
Minor Effect ◽  
European Alps ◽  
Atmospheric Conditions ◽  
Glacier Surface ◽  
Terrestrial Lidar ◽  
Physical Weathering ◽  
Ice Surface ◽  
Recent Climate ◽  
Ample Supply ◽  
A Minor

Abstract. In the European Alps almost half the glacier volume disappeared over the past 150 years. The loss is reflected in glacier retreat and ice surface lowering even at high altitude. In steep glacial cirques surface lowering exposes rock to atmospheric conditions for the very first time in many millennia. Instability of rockwalls has long been identified as one of the direct consequences of deglaciation, but so far cirque-wide quantification of rockfall at high-resolution is missing. Based on terrestrial LiDAR a rockfall inventory for the permafrost-affected rockwalls of two rapidly deglaciating cirques in the Central Alps of Austria (Kitzsteinhorn) is established. Over six-years (2011–2017) 78 rockwall scans were acquired to generate data of high spatial and temporal resolution. 632 rockfalls were registered ranging from 0.003 to 879.4 m³, mainly originating from pre-existing structural rock weaknesses. 60 % of the rockfall volume detached from less than ten vertical meters above the glacier surface, indicating enhanced rockfall activity over tens of years following deglaciation. Debuttressing seems to play a minor effect only. Rather, preconditioning is assumed to start inside the Randkluft (gap between cirque wall and glacier) where sustained freezing and ample supply of liquid water likely cause enhanced physical weathering and high plucking stresses. Following deglaciation, pronounced thermomechanical strain is induced and an active layer penetrates into the formerly perennially frozen bedrock. These factors likely cause the observed paraglacial rockfall increase close to the glacier surface. This paper presents the most extensive dataset of high-alpine rockfall to date and the first systematic documentation of a cirque-wide erosion response of glaciated rockwalls to recent climate warming.

The age of dust—A new hydrological indicator in arid environments?

Geology ◽  
2021 ◽  
Author(s):  
Simon Turner ◽  
Heather Handley ◽  
Paul Hesse ◽  
Bruce Schaefer ◽  
Anthony Dosseto
Keyword(s):  
Trace Element ◽  
River Sediments ◽  
Preliminary Evidence ◽  
Arid Environments ◽  
Physical Weathering ◽  
Uranium Series ◽  
Fluvial Transport ◽  
And Storage ◽  
Isotope Analyses ◽  
Dust Deposits

Dust plays important roles in the environment, and there has been much interest in the formation, provenance, and age of the world’s dust deposits. Ongoing debates are concerned with the importance of glacial grinding versus eolian abrasion and fluvial transport in the formation of silt-sized particles. Short-lived uranium-series isotopes afford new insights because they can be used both for provenance fingerprinting and for constraining the integrated age of chemical and physical weathering and subsequent transport and storage of sediments. Here we present trace element and Sr, Nd, and U-series isotope analyses from a number of Australian dusts and suspended river sediments remobilized during floods a year later. The inferred ages of the Australian dust appear to be linked to aridification and the loss of inland megalakes ~30–120 k.y. ago. This provides preliminary evidence that the age of dust may provide a new hydrological indicator in arid environments.

The role of freezing-thaw cycling in rock samples topography evolution and rock cliff retreat

2021 ◽  
Author(s):  
Li Fei ◽  
Marc-Henri Derron ◽  
Tiggi Choanji ◽  
Michel Jaboyedoff ◽  
Chunwei Sun ◽  
...  
Keyword(s):  
Freezing Point ◽  
Meteorological Data ◽  
Test Chamber ◽  
Monitoring Program ◽  
Dynamic Environment ◽  
Rock Properties ◽  
Rock Surface ◽  
Physical Weathering ◽  
Rock Samples

<p>Freezing-thaw weathering is recognized as one of the most significant factors in the fatigue of rock mass in areas where the temperature periodically fluctuates around the freezing point. <br>A one-year monthly SfM monitoring program from December 19, 2019, to January 7, 2021, was done to detect rockfall activity on a rockslide cliff composed of marl-sandstone at La Cornalle, Switzerland. More than one hundred rockfall events were detected during this period with the volumes varied from 0.005m<sup>3</sup> to 4.85m<sup>3</sup>. <br>We texture all the rockfalls on the 3D SfM model. It is shown that most of them are mainly located in three areas:  the top of the cliff, the foot of the cliff, and the medium-left part of the cliff. The common feature of these three parts is that the layers are more or less overhanging with dense fractures around them. At the same time, the meteorological data collected by a weather station on site is correlated with the rockfall events to figure out the relationship between each other. Actually, about 30% of total rockfall volume fell during winter on this site. The triggering factor of rockfall during winter is related to freezing-thaw cycling. This kind of weathering can be understood as an interplay between rock properties and its dynamic environment.<br>In order to make clear the role of freezing-thaw played on the rockfall generation, an on-site 24h monitoring measurement program that consists of two crack meters, one rock thermal sensor, and thermal camera monitoring is installed in January 2021. Those datasets will help to understand how the crack grows with the changing temperature. In addition, freezing-thaw cycling laboratory experiments for the rock samples taken from different areas of the cliff will be done with an environmental test chamber. The topography of the rock samples before and after the experiments will be acquired by a 3D handheld scanner. This work will benefit to reveal the rock surface evolution during the freezing-thaw cycling in a dynamic environment with varied humidity and number of cycles. <br>In conclusion, the combination of on-site measurements and laboratory freezing-thaw experiments will provide a good basis for a better understanding of the rockfall triggering mechanism led by physical weathering.</p>

The role of erosion in the morphometry of composite volcanoes

2021 ◽  
Author(s):  
Roos van Wees ◽  
Pierre-Yves Tournigand ◽  
Daniel O’Hara ◽  
Pablo Grosse ◽  
Gabor Kereszturi ◽  
...  
Keyword(s):  
Fractal Dimension ◽  
Age Determination ◽  
Morphometric Parameters ◽  
Physical Weathering ◽  
Erosion Rates ◽  
Erosion Processes ◽  
Digital Elevation ◽  
Shape Complexity ◽  
Geochronological Constraints ◽  
Natural Composite

<p>Volcanoes are extremely dynamic landforms. They grow by the accumulation of eruptive products and intrusions and degrade by a range of erosion processes such as superficial runoff, chemical and physical weathering, fluvial and glacial incision, and mass movements. In this study, we aim at documenting and quantifying the morphology of natural composite volcanoes using a range of morphometric indices, to better understand the factors that control erosion rates and patterns.</p><p>In addition to standard morphometric indices, including edifice ellipticity and irregularity, computed by the MORVOLC algorithm, a fractal dimension tool is developed to quantitatively report the shape complexity of stratovolcanoes. A convex hull approach is used to derive minimal erosion volumes and estimate erosion rates, considering available geochronological constraints. Morphometric parameters are derived from digital elevation models (DEMs) for a few exemplary stratovolcanoes of contrasted ages from the same volcanic region. To analyse the potential bias induced by the selected DEMs and the identification of the volcanic edifice outline, we also conduct a sensitivity analysis. The morphometric parameters are similarly extracted using the freely and globally available ALOS 30m (AW3D30), SRTM 30m (SRTMGL1), and ASTER 30m (GDEM 003), and compared to values obtained with the TanDEM-X 12m. The subjective user-drawn edifice outlines are compared to outlines generated by available algorithms, i.e. NETVOLC and MBOA, and their impact on the accuracy of morphometric indexes is quantified.  </p><p>Our results highlight that erosion increases edifice irregularity and fractal dimension. Preliminary trends between volcano fractal dimension, eroded volume, and age suggest that fractal analysis has the potential to be used as a relative age determination tool. The proposed morphometric characterisation paves the way for a comparison between natural volcanoes and controlled lab experiments reproducing the degradation of pristine volcanic cones by surface runoff to be developed later in our project.  </p>

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