scholarly journals Arc volcanism, carbonate platform evolution and palaeo-atmospheric CO<sub>2</sub>: Components and interactions in the deep carbon cycle

2017 ◽  
Author(s):  
Jodie Pall ◽  
Sabin Zahirovic ◽  
Sebastiano Doss ◽  
Rakib Hassan ◽  
Kara J. Matthews ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Carbonate Platform ◽  
Global Climate ◽  
Atmospheric Co2 ◽  
Wavelet Coherence ◽  
Plate Motion ◽  
Carbonate Platforms ◽  
Volcanic Emissions ◽  
Coupled Models ◽  
Co2 Levels

Abstract. Carbon dioxide (CO2) liberated at arc volcanoes that intersect buried carbonate platforms plays a larger role in influencing atmospheric CO2 than those active margins lacking buried carbonate platforms. This study investigates the contribution of carbonate-intersecting arc activity on palaeo-atmospheric CO2 levels over the past 410 million years by integrating a plate motion model with an evolving carbonate platform development model. Our modelled subduction zone lengths and carbonate-intersecting arc lengths approximate arc activity with time, and can be used as input into fully-coupled models of CO2 flux between deep and shallow reservoirs. Continuous and cross-wavelet as well as wavelet coherence analyses were used to evaluate trends between carbonate-intersecting arc activity, non-carbonate-intersecting arc activity and total global subduction zone lengths and the proxy-CO2 record between 410 Ma and the present. Wavelet analysis revealed significant linked periodic behaviour between 75–50 Ma, where global carbonate-intersecting arc activity is relatively high and where peaks in palaeo-atmospheric CO2 is correlated with peaks in global carbonate-intersecting arc activity, characterised by a ~ 32 Myr periodicity and a 10 Myr lag of CO2 peaks after carbonate-intersecting arc length peaks. The linked behaviour may suggest that the relative abundance of carbonate-intersecting arcs played a role in affecting global climate during the Late Cretaceous to Early Paleogene greenhouse. At all other times, atmospheric CO2 emissions from carbonate-intersecting arcs were not correlated with the proxy-CO2 record. Our analysis did not support the idea that carbonate-intersecting arc activity is more important than non-carbonate intersecting arc activity in driving changes in palaeo-atmospheric CO2 levels. This suggests that tectonic controls are more elaborate than the subduction-related volcanic emissions component or that other feedback mechanisms between the geosphere, atmosphere and biosphere played larger roles in modulating climate in the Phanerozoic.

scholarly journals The influence of carbonate platform interactions with subduction zone volcanism on palaeo-atmospheric CO<sub>2</sub> since the Devonian

2018 ◽  
Vol 14 (6) ◽  
pp. 857-870 ◽  
Author(s):  
Jodie Pall ◽  
Sabin Zahirovic ◽  
Sebastiano Doss ◽  
Rakib Hassan ◽  
Kara J. Matthews ◽  
...  
Keyword(s):  
Subduction Zone ◽  
Subduction Zones ◽  
Carbonate Platform ◽  
Atmospheric Co2 ◽  
Wavelet Coherence ◽  
Plate Motion ◽  
Magmatic Activity ◽  
Carbonate Platforms ◽  
Coupled Models ◽  
Platform Development

Abstract. The CO2 liberated along subduction zones through intrusive/extrusive magmatic activity and the resulting active and diffuse outgassing influences global atmospheric CO2. However, when melts derived from subduction zones intersect buried carbonate platforms, decarbonation reactions may cause the contribution to atmospheric CO2 to be far greater than segments of the active margin that lacks buried carbon-rich rocks and carbonate platforms. This study investigates the contribution of carbonate-intersecting subduction zones (CISZs) to palaeo-atmospheric CO2 levels over the past 410 million years by integrating a plate motion and plate boundary evolution model with carbonate platform development through time. Our model of carbonate platform development has the potential to capture a broader range of degassing mechanisms than approaches that only account for continental arcs. Continuous and cross-wavelet analyses as well as wavelet coherence are used to evaluate trends between the evolving lengths of carbonate-intersecting subduction zones, non-carbonate-intersecting subduction zones and global subduction zones, and are examined for periodic, linked behaviour with the proxy CO2 record between 410 Ma and the present. Wavelet analysis reveals significant linked periodic behaviour between 60 and 40 Ma, when CISZ lengths are relatively high and are correlated with peaks in palaeo-atmospheric CO2, characterised by a 32–48 Myr periodicity and a ∼ 8–12 Myr lag of CO2 peaks following CISZ length peaks. The linked behaviour suggests that the relative abundance of CISZs played a role in affecting global climate during the Palaeogene. In the 200–100 Ma period, peaks in CISZ lengths align with peaks in palaeo-atmospheric CO2, but CISZ lengths alone cannot be determined as the cause of a warmer Cretaceous–Jurassic climate. Nevertheless, across the majority of the Phanerozoic, feedback mechanisms between the geosphere, atmosphere and biosphere likely played dominant roles in modulating climate. Our modelled subduction zone lengths and carbonate-intersecting subduction zone lengths approximate magmatic activity through time, and can be used as input into fully coupled models of CO2 flux between deep and shallow carbon reservoirs.

scholarly journals GIS-Based Approach to Spatio-Temporal Interpolation of Atmospheric CO2 Concentrations in Limited Monitoring Dataset

Atmosphere ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 384
Author(s):  
Yaroslav Bezyk ◽  
Izabela Sówka ◽  
Maciej Górka ◽  
Jan Blachowski
Keyword(s):  
Seasonal Variability ◽  
Sampling Strategy ◽  
Climate Impacts ◽  
Air Pollutant ◽  
Urban Atmosphere ◽  
Atmospheric Co2 ◽  
Spatial Characteristic ◽  
Interpolation Methods ◽  
Co2 Levels ◽  
The City

Understanding the magnitude and distribution of the mixes of the near-ground carbon dioxide (CO2) components spatially (related to the surface characteristics) and temporally (over seasonal timescales) is critical to evaluating present and future climate impacts. Thus, the application of in situ measurement approaches, combined with the spatial interpolation methods, will help to explore variations in source contribution to the total CO2 mixing ratios in the urban atmosphere. This study presents the spatial characteristic and temporal trend of atmospheric CO2 levels observed within the city of Wroclaw, Poland for the July 2017–August 2018 period. The seasonal variability of atmospheric CO2 around the city was directly measured at the selected sites using flask sampling with a Picarro G2201-I Cavity Ring-Down Spectroscopy (CRDS) technique. The current work aimed at determining the accuracy of the interpolation techniques and adjusting the interpolation parameters for estimating the magnitude of CO2 time series/seasonal variability in terms of limited observations during the vegetation and non-vegetation periods. The objective was to evaluate how different interpolation methods will affect the assessment of air pollutant levels in the urban environment and identify the optimal sampling strategy. The study discusses the schemes for optimization of the interpolation results that may be adopted in areas where no observations are available, which is based on the kriging error predictions for an appropriate spatial density of measurement locations. Finally, the interpolation results were extended regarding the average prediction bias by exploring additional experimental configurations and introducing the limitation of the future sampling strategy on the seasonal representation of the CO2 levels in the urban area.

About this title - Seismic Characterization of Carbonate Platforms and Reservoirs

10.1144/sp509 ◽  
2021 ◽  
Vol 509 (1) ◽  
pp. NP-NP
Author(s):  
J. Hendry ◽  
P. Burgess ◽  
D. Hunt ◽  
X. Janson ◽  
V. Zampetti
Keyword(s):  
Seismic Data ◽  
Oil And Gas ◽  
Carbonate Platform ◽  
Carbonate Platforms ◽  
Oil And Gas Exploration ◽  
Seismic Modelling ◽  
Flow Units ◽  
Development Data ◽  
Seismic Characterization

Modern seismic data have become an essential toolkit for studying carbonate platforms and reservoirs in impressive detail. Whilst driven primarily by oil and gas exploration and development, data sharing and collaboration are delivering fundamental geological knowledge on carbonate systems, revealing platform geomorphologies and how their evolution on millennial time scales, as well as kilometric length scales, was forced by long-term eustatic, oceanographic or tectonic factors. Quantitative interrogation of modern seismic attributes in carbonate reservoirs permits flow units and barriers arising from depositional and diagenetic processes to be imaged and extrapolated between wells.This volume reviews the variety of carbonate platform and reservoir characteristics that can be interpreted from modern seismic data, illustrating the benefits of creative interaction between geophysical and carbonate geological experts at all stages of a seismic campaign. Papers cover carbonate exploration, including the uniquely challenging South Atlantic pre-salt reservoirs, seismic modelling of carbonates, and seismic indicators of fluid flow and diagenesis.

scholarly journals Multi-scale investigation on streamflow temporal variability and its connection to global climate indices for unregulated rivers in India

2021 ◽  
Author(s):  
Pavan Kumar Yeditha ◽  
Tarun Pant ◽  
Maheswaran Rathinasamy ◽  
Ankit Agarwal
Keyword(s):  
Wavelet Transform ◽  
Temporal Variability ◽  
Global Climate ◽  
Phase Relationship ◽  
Wavelet Coherence ◽  
Climate Indices ◽  
Coherence Analysis ◽  
Cross Wavelet Transform ◽  
Wavelet Coherence Analysis ◽  
Cross Wavelet

Abstract With the increasing stress on water resources for a developing country like India, it is pertinent to understand the dominant streamflow patterns for effective planning and management activities. This study investigates the spatiotemporal characterization of streamflow of six unregulated catchments in India. Firstly, Mann Kendall (MK) and Changepoint analysis were carried out to detect the presence of trends and any abrupt changes in hydroclimatic variables in the chosen streamflows. To unravel the relationships between the temporal variability of streamflow and its association with precipitation and global climate indices, namely, Niño 3.4, IOD, PDO, and NAO, continuous wavelet transform is used. Cross-wavelet transform and wavelet coherence analysis was also used to capture the coherent and phase relationships between streamflow and climate indices. The continuous wavelet transforms of streamflow data revealed that intra-annual (0.5 years), annual (1 year), and inter-annual (2–4 year) oscillations are statistically significant. Furthermore, a better understanding of the in-phase relationship between the streamflow and precipitation at intra-annual and annual time scales were well-captured using wavelet coherence analysis compared to cross wavelet transform. Furthermore, our analysis also revealed that streamflow observed an in-phase relationship with IOD and NAO, whereas a lag correlation with Niño 3.4 and PDO indices at intra-annual, annual and interannual time scales.

scholarly journals Seismic characterisation of carbonate platforms and reservoirs: an introduction and review

2021 ◽  
pp. SP509-2021-51
Author(s):  
J. Hendry ◽  
P. Burgess ◽  
D. Hunt ◽  
X. Janson ◽  
V. Zampetti
Keyword(s):  
Seismic Data ◽  
Large Scale ◽  
Carbonate Platform ◽  
Energy Transition ◽  
Carbonate Platforms ◽  
Seismic Attribute ◽  
Sequence Stratigraphic ◽  
3D Data ◽  
Diagenetic Facies ◽  
Central Atlantic

AbstractImproved seismic data quality in the last 10–15 years, innovative use of seismic attribute combinations, extraction of geomorphological data, and new quantitative techniques, have significantly enhanced understanding of ancient carbonate platforms and processes. 3D data have become a fundamental toolkit for mapping carbonate depositional and diagenetic facies and associated flow units and barriers, giving a unique perspective how their relationships changed through time in response to tectonic, oceanographic and climatic forcing. Sophisticated predictions of lithology and porosity are being made from seismic data in reservoirs with good borehole log and core calibration for detailed integration with structural, paleoenvironmental and sequence stratigraphic interpretations. Geologists can now characterise entire carbonate platform systems and their large-scale evolution in time and space, including systems with few outcrop analogues such as the Lower Cretaceous Central Atlantic “Pre-Salt” carbonates. The papers introduced in this review illustrate opportunities, workflows, and potential pitfalls of modern carbonate seismic interpretation. They demonstrate advances in knowledge of carbonate systems achieved when geologists and geophysicists collaborate and innovate to maximise the value of seismic data from acquisition, through processing to interpretation. Future trends and developments, including machine learning and the significance of the energy transition, are briefly discussed.

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