Conveners
Applications of Cosmogenic Isotopes
- David Fink (ansto)
Applications of Cosmogenic Isotopes
- David Fink (ansto)
Applications of Cosmogenic Isotopes
- Fusa Miyake (ISEE, Nagoya University)
Applications of Cosmogenic Isotopes
- Marc Caffee (Purdue University)
Description
Applications involving isotopes created via cosmic ray activation and spallation. Topics include exposure dating and groundwater tracing.
Solar eruptions (solar flares and coronal mass ejections) are known to cause various space–weather phenomena in the Sun–Earth system that can have severe impacts on modern society. As the magnitude of a solar eruption increases, its frequency of occurrence decreases, but the severity of its impact increases. Therefore, it is important to understand the long-term characteristics of extreme...
Radionuclides are ideal gauges for monitoring the energetic particle environment of the lunar surface and near sub-surface. The physics of the production mechanisms of the radionuclides and the production rates are known. The measurement of radionuclides in depth profiles from the lunar surface has allowed us to better characterize both the galactic and cosmic ray fluxes in addition to...
Previous research has revealed that the 10Be record in laminated travertine has significant potential for reconstructing past high-resolution solar activity. However, the depositional processes of atmospheric 10Be into travertine have not been entirely resolved, therefore the methodology for extracting the production signal is not well established. In this study, we present an annually...
The well-preserved Tswaing Meteor Crater– aka Pretoria Saltpan – with a diameter of 1130 m is located ca. 40 km NNW of Tshwane (Pretoria). It has been a subject of several scientific investigations. The crater is formed on a ca. 2 Ga Nebo Granite, the acid phase, of the Bushveld Complex (Lebowa Granite Suite). The interior structure floor is not far removed from the local ground water level...
Understanding the hydrological changes on context of global warming is of special significance for the security and sustainable development in vast arid areas of Central Asia. The sustainability of river runoff, as the major freshwater source in arid Central Asia, is of special concerns because millions of people suffer from water stress. However, our understanding of the freshwater mechanisms...
The Guizhou Plateau is a typical subtropical mountainous karst area where carbonate rocks contain very few insoluble residues causing the slow soil production rate. Moreover, serious soil erosion leads to karst rocky desertification and land degradation in this area. Quantification of soil formation age and rate thus is vital for understanding carbonate weathering and scientifically evaluating...
Landscape evolution is a fundamental and vital topic in natural geography science, which is of great significance for understanding Earth’s dynamics, climate change, geohazard prevention and human habitability. Surface denudation, referring to the sum of chemical weathering and physical erosion, is an essential process to drive landscape shaping and transformation. In details, chemical...
Surface weathering and permafrost exhumation rates in the Transantarctic Mountains are important for understanding landscape evolution, determining onset of persistent polar climate conditions, and refining East Antarctic Ice Sheet response to past climate perturbations. We report cosmogenic 10Be and 26Al in bedrock, erratics, a 3m permafrost depth-profile and cobbles embedded within Sirius...
The Laschamp geomagnetic dipole low, associated with a pronounced geomagnetic excursion that occurred at about 41.5 ka, has been studied in several authigenic beryllium isotope records from deep-sea sediments. However, such records from the Southern Hemisphere were scarce. In this study, we analyzed the authigenic beryllium isotope (the 10Be/9Be ratio) from 48 to 29 ka in a sediment core (the...
The deep-sea ferromanganese crust (DSFC) is not only an ideal archive for recording the history of the Earth’s evolution, but also a natural reservoir for rich in a variety of metal elements. As one of the most important cosmogenic nuclides, as well as an ideal indictor of natural events since Quaternary, 26Al has not been as widely used in chronological studies as 14C, 10Be etc., due to the...
Age determination of sediments in arid and hyper-arid regions poses challenges due to the absence of age-indicating fossils. As part of the collaborative research cluster 1211 of the German Research Foundation “Earth - Evolution at the Dry Limit” we are improving cosmogenic radionuclide dating in order to gain a better insight into the geological dynamics of, e.g., the Atacama Desert or the...
In situ-produced Be-10 is routinely used in the mineral quartz for measuring exposure times and erosion rates. Most previous applications have focused on relatively coarse mineral grains (typically greater than 100 microns) in sandstone, quartz veins, or igneous and metamorphic rocks. Here we report Be-10 measurements from fine-grained quartz extracted from shale bedrock and sediment. Shale...
Terrestrial cosmogenic nuclides provide a crucial tool in geomorphology, however evaluation and correction of systematic uncertainties remains a challenge in estimating denudation rates of land surfaces. Subsurface nuclide production involves distinct processes by neutron and muons, which have different contribution ratios and attenuation lengths for accumulating any nuclides such as...
In radioisotope dating, statistical fluctuations of atom counts or decay counts can sometimes lead to unphysical results, such as negative counts after subtracting the background or negative apparent ages near the boundaries of the dating range. How to treat these boundary cases with a unified approach and give proper estimates on age limits and confidence intervals is an important issue in...
The rate of production of cosmogenic nuclides is not only related to altitude and latitude, but also to topographic occlusion and the elemental composition of rock formations. Due to the occlusion of the terrain, it is necessary to establish a shielding factor calculation model in practical geoscience applications. In this paper, five geometric shapes of terrain are considered: slope, surface...
