20 research outputs found

    Expedition 381 Summary

    Full text link
    The primary objective of International Ocean Discovery Program Expedition 381 was to retrieve a record of early continental rifting and basin evolution from the Corinth rift, central Greece. Continental rifting is fundamental for the formation of ocean basins, and active rift zones are dynamic regions of high geohazard potential. However, the detailed spatial and temporal evolution of a complete rift system needed to understand rift development from the fault to plate scale is poorly resolved. In the active Corinth rift, deformation rates are high, the recent synrift succession is preserved and complete offshore, and earlier rift phases are preserved onshore. Additionally, a dense seismic database provides high-resolution imaging of the fault network and seismic stratigraphy around the basin. As the basin has subsided, its depositional environment has been affected by fluctuating global sea level and its absolute position relative to sea level, and the basin sediments record this changing environment through time. In Corinth, we can therefore achieve an unprecedented precision of timing and spatial complexity of rift-fault system development, rift-controlled drainage system evolution, and basin fill in the first few million years of rift history. The following are the expedition themes: High-resolution fault slip and rift evolution history, Surface processes in active rifts, High-resolution late Quaternary Eastern Mediterranean paleoclimate and paleoenvironment of a developing rift basin, and Geohazard assessment in an active rift. These objectives were and will be accomplished as a result of successful drilling, coring, and logging at three sites in the Gulf of Corinth, which collectively yielded 1645 m of recovered core over a 1905 m cored interval. Together, these cores provide (1) a long rift history (Sites M0078 and M0080), (2) a high-resolution record of the most recent phase of rifting (Site M0079), and (3) the spatial variation of rift evolution (comparison of sites in the central and eastern rift). The sediments contain a rich and complex record of changing sedimentation, sediment and pore water geochemistry, and environmental conditions from micropaleontological assemblages. The preliminary chronology developed by shipboard analyses will be refined and improved during postexpedition research, providing a high-resolution chronostratigraphy down to the orbital timescale for a range of tectonic, sedimentological, and paleoenvironmental studies. This chronology will provide absolute timing of key rift events, rates of fault movement, rift extension and subsidence, and the spatial variations of these parameters. The core data will also allow us to investigate the relative roles of and feedbacks between tectonics, climate, and eustasy in sediment flux, basin evolution, and basin environment. Finally, the Corinth rift boreholes will provide the first long Quaternary record of Mediterranean-type climate in the region. The potential range of scientific applications for this unique data set is very large, encompassing tectonics, sedimentary processes, paleoenvironment, paleoclimate, paleoecology, geochemistry, and geohazards

    High-resolution record reveals climate-driven environmental and sedimentary changes in an active rift

    Get PDF
    Young rifts are shaped by combined tectonic and surface processes and climate, yet few records exist to evaluate the interplay of these processes over an extended period of early rift-basin development. Here, we present the longest and highest resolution record of sediment flux and paleoenvironmental changes when a young rift connects to the global oceans. New results from International Ocean Discovery Program (IODP) Expedition 381 in the Corinth Rift show 10s–100s of kyr cyclic variations in basin paleoenvironment as eustatic sea level fluctuated with respect to sills bounding this semi-isolated basin, and reveal substantial corresponding changes in the volume and character of sediment delivered into the rift. During interglacials, when the basin was marine, sedimentation rates were lower (excepting the Holocene), and bioturbation and organic carbon concentration higher. During glacials, the basin was isolated from the ocean, and sedimentation rates were higher (~2–7 times those in interglacials). We infer that reduced vegetation cover during glacials drove higher sediment flux from the rift flanks. These orbital-timescale changes in rate and type of basin infill will likely influence early rift sedimentary and faulting processes, potentially including syn-rift stratigraphy, sediment burial rates, and organic carbon flux and preservation on deep continental margins worldwide

    High-resolution record revealsclimate-driven environmental andsedimentary changes in an active rift

    Get PDF
    Young rifts are shaped by combined tectonic and surface processes and climate, yet few records exist to evaluate the interplay of these processes over an extended period of early rift-basin development. Here, we present the longest and highest resolution record of sediment flux and paleoenvironmental changes when a young rift connects to the global oceans. New results from International Ocean Discovery Program (IODP) Expedition 381 in the Corinth Rift show 10s–100s of kyr cyclic variations in basin paleoenvironment as eustatic sea level fluctuated with respect to sills bounding this semi-isolated basin, and reveal substantial corresponding changes in the volume and character of sediment delivered into the rift. During interglacials, when the basin was marine, sedimentation rates were lower (excepting the Holocene), and bioturbation and organic carbon concentration higher. During glacials, the basin was isolated from the ocean, and sedimentation rates were higher (~2–7 times those in interglacials). We infer that reduced vegetation cover during glacials drove higher sediment flux from the rift flanks. These orbital-timescale changes in rate and type of basin infill will likely influence early rift sedimentary and faulting processes, potentially including syn-rift stratigraphy, sediment burial rates, and organic carbon flux and preservation on deep continental margins worldwide.publishedVersio

    Some Parametric Factors Influencing Cottage Ethanol Plant

    No full text
    Abstract: A cottage ethanol plant was designed, constructed and tested in major effect to make reasonable contribution in the current drive for renewable energy. The plant consists of a stoker chamber, fermentation vessel, two-stage distillation column, a condenser and the ethanol receptacle. The conditioned feedstock, freshly harvested cassava, was feed into the fermentation vessel, allowed 48 h fermentation with enzymes and yeast added. The ethanol was distilled and allowed to pass through a condenser and finally the ethanol was collected. The ethanol unit prototype was evaluated using tests on three varieties of cassava. The degree of recovery of the distilled sample ranged from 18.28 % ethanol for 3-5 mm Cassava chips to 62.03% ethanol by volume for sieved cassava liquor on one hand, and ranged from 49.37% of ethanol for a packing size of 3-6 mm to 62.81% of ethanol for a packing size of 8-10 mm. Mean values of some tests parameters were also determined. These parameters as quantitatively analysed using ANOVA, showed high significant difference (p<0.01) for the conditioned samples effect on volume of sample, percentage ethanol, density and refractive index, but was just significant (p<0.05) for the effect of variety of feedstock on density and percentage ethanol while having no significant effect on the volume of sample and refractive index. With the change in the design figuration of the condenser, the ANOVA result showed high significant (p<0.01) effect on volume of sample, significant (p<0.05) effect on percentage ethanol, density and refractive index. The varieties however, showed no significant effect on density

    A Descriptive Analysis of the Institutional Frameworks for Disaster Management in Uganda: Structures, Functions and Gaps

    No full text
    Background:There is insufficient documentation of the institutional frameworks for disaster management and resilience at different levels in sub-Saharan Africa. The objective of this study was to describe the institutional framework for disaster management in Uganda, and to identify actionable gaps at the different levels. Methods: This was part of a multi-country assessment in which 6 countries in Eastern Africa developed and applied a common tool. The assessment was qualitative in nature employing a mixed methods approach including review of documents, interviews with key informants from agencies involved in disaster management in Uganda, group discussions with stakeholder and synthesis meetings of the assessment team. Findings: The Office of the Prime Minister is the lead agency for disaster management, but management of disasters of a technical nature is devolved to line ministries (e.g. epidemics by the Health Ministry and Epizootics by the Agriculture Ministry). A new policy spells out disaster management structures at national, district, subcounty, and village levels. Key challenges included coordination, more focus on prevention than risk reduction, differences in capacity between sectors and inadequate inter-sectoral collaboration. The new policy and structures have not yet been rolled out to districts and sub-district levels, and districts lack a line item budget for disaster capacity building. Conclusions: The institutional framework for disaster management in Uganda needs to be strengthened at all levels through initiation of the relevant structures, training, and resource allocation so that they develop disaster management plans.Keywords: Institutional framework, disaster, disaster managemen
    corecore