Isotope O change by slope depth
Best insight from top research papers
The oxygen isotopic composition can change with depth, as indicated by various studies. For instance, research in the Southern Ocean revealed that the slope of the oxygen isotope-salinity relationship varied with depth, showing different origins of water masses at different depths . In another study, the δ18O values in chert decreased with increasing sub-bottom depth, suggesting different temperatures of formation at various depths . Additionally, investigations in hillslope agro-ecosystems demonstrated distinct isotopic signatures in soil water at different depths, indicating varied infiltration patterns and the possible existence of a low permeable layer at around 60 cm depth . Moreover, experiments on hillslopes in a mountainous catchment showed different shapes of depth profiles of deuterium in relation to hillslope position, highlighting the influence of topography on isotopic signals at different depths .
Answers from top 5 papers
More filters
| Papers (5) | Insight |
|---|---|
| Yes, the stable isotope profiles of oxygen (O) change with depth, as shown by the study's monitoring of water stable isotope profiles in an evaporating soil column. | |
| The isotopic signature of oxygen (δ18O) in soil water changes with slope depth, indicating varying infiltration patterns and the possible presence of a low permeable layer around 60 cm depth. | |
| The oxygen isotope change varies with depth due to different hydrological processes, as indicated by the slope of the oxygen isotope-salinity relationship in the Southern Ocean. | |
| The isotopic composition of water (O) changes with slope depth, showing distinct patterns related to wetness affinity and subsurface flow paths along hillslopes. | |
Open access 01 Jan 2006 | The oxygen isotope composition in chert decreases with increasing sub-bottom depth, indicating varying formation temperatures. The slope of the δO/depth curve differs among sites, suggesting different thermal histories. |
Related Questions
Isotope O change by depth4 answersOxygen isotopes do change with depth in various marine organisms. Studies on deep-sea squid Spirula spirula show migration patterns from >1,000 m depths to shallower waters at 400–600 m depths based on δ18O values. Similarly, research on Southern Ocean dynamics reveals oxygen isotopic variability at intermediate depths, indicating different water masses and origins. Tuna otolith analysis demonstrates δ18O changes during life stages, reflecting habitat shifts from ocean surface to deep-sea bottom. Coral Porites lutea studies show depth-dependent δ18O variations, suggesting kinetic effects on isotopic composition in deep-water corals. Foraminifera shell analysis indicates δ18O differences between chambers, implying ontogenetic depth migration and potential offsets from surface signals. Overall, these studies collectively support the notion that oxygen isotopes indeed change with depth in marine environments.
How does the isotopic composition of δ18O, δ2H, δ 13C vary between source water, plant tissue and xylem wood?5 answersThe isotopic composition of δ18O and δ2H in plant tissues and xylem wood can vary significantly from source water due to various factors. Studies have shown that there are systematic differences in isotopic signatures based on sampling height within trees, indicating the importance of considering water residence times within trees. Additionally, isotopic heterogeneities between different xylem compartments and soil water pools have been observed, suggesting that not all isotopic mismatches can be attributed to methodological artifacts. Furthermore, species-specific fractionation of δ18O and δ2H has been identified in tropical trees, impacting water source identification and evapotranspiration partitioning. The isotopic signatures in xylem water can also be influenced by tree physiology and biochemistry, leading to differences in isotopic enrichment along the root-twig flow path. Vegetation variables, such as tree species and diameter, play a significant role in explaining the spatial variability of xylem stable water isotopes in forest ecosystems.
Isotopes in hyporheic zone4 answersIsotopes are widely used in studying the hyporheic zone. They provide valuable information about the origin of groundwater and can be used to evaluate groundwater rapidity and travel periods. Stable isotopes of water, such as deuterium, have been used to investigate groundwater-surface water interactions in the hyporheic area. Additionally, isotopic signatures of water samples collected from different depths in streams have shown variations following depth, sampling time, and location. Radon-222, a radioactive noble gas, has been used as a tracer to determine residence times in the hyporheic zone. It has been found that radon-based residence time estimates can resolve residence times on the order of a few hours, allowing for the study of fast and small-scale exchange processes. Overall, isotopes play a crucial role in understanding the hydrological and biogeochemical functioning of the hyporheic zone.
Why does the pH of the ocean increase with depth?5 answersThe pH of the ocean increases with depth due to various factors. One possible explanation is the increased use of dissolved bicarbonate in the surface ocean for photosynthesis during glacial times, which enriches the glacial organic matter in 13C and causes an increase in oceanic pH. Another factor is the fractionation of boron isotopes between seawater and precipitated carbonate minerals, which is pH-dependent. This has been used to estimate changes in ocean pH over time, with records indicating higher pH during the last glaciation. Additionally, the presence of carbonates plays a role in determining ocean pH, with the absence and presence of carbonates limiting the range of pH values. These factors contribute to the overall increase in ocean pH with depth.
How carbon stability elvolves with soil depth?4 answersCarbon stability in soil evolves with depth, with different patterns observed in different studies. In drained peatlands, deeper soil layers were found to be more sensitive to plant carbon, particularly complex or recalcitrant carbon, than surface soil layers. In pasture soils, the fine fraction soil in the topsoil was found to have a larger stable carbon fraction, while plant material in the coarse fraction was less stable. In forest soils, significant amounts of organic carbon were found to accumulate in subsoil layers below 30 cm, with the stability of soil carbon varying between different subsoil depth increments. In chronosequences along a climate gradient, the stability of soil organic matter generally increased with depth in fluvial terraces, while it remained constant in fluvio-glacial terraces. In deep-rooted crops, carbon input through rhizodeposition declined with depth, but even small amounts of carbon allocated to deep soil layers became microbially stabilized.
When does enamel acquire its oxygen isotope composition?2 answersEnamel acquires its oxygen isotope composition during the process of fossilization, which occurs early on and remains relatively stable afterwards. The oxygen isotope composition of enamel can be used as a proxy for local surface temperature, making it a valuable tool for studying climate change and its impact on human societies. Stable hydrogen isotopes in tooth enamel apatite also correlate with local meteoric water, but the relationship between hydrogen isotopes and enamel composition is more complex and influenced by factors such as adsorbed water and laboratory conditions. Oxygen isotope analysis of modern foodwebs has shown promising results for paleoecological research, indicating that oxygen isotope compositions within mammalian tooth enamel can provide valuable ecological information. Understanding enamel diagenesis is crucial for accurate isotopic palaeodietary and palaeoenvironmental reconstructions, as subtle alterations in isotopic signatures can occur during the fossilization process.