835 research outputs found

    Introduction & Table of Cases

    Get PDF
    Commissions of inquiry have been popular mechanisms with Canadian governments. Despite a widespread view that they are used principally to delay action while removing embarrassment from the immediate vicinity of governments, it is a fact that commissions of inquiry have repeatedly - and often highly successfully - served as vehicles for analyzing policy, for evaluating outworn or failed policy, for identifying a consensus about policy and for building support for new policy directions. They have brought facts to light both about specific incidents and about matters of policy concern; facts as diverse as what actually happened at a given time and place and the real makeup of public opinion on the subject matter of the inquiry. The roster of inquiries that have served in these capacities is long and impressive

    Chironomid-inferred summer temperature development during the late Rissian glacial, Eemian interglacial and earliest Würmian glacial at Füramoos, southern Germany

    Get PDF
    Eemian pollen records from central Europe describe a transition from thermophilous tree taxa in the early Eemian to boreal tree taxa in the late Eemian with forest opening in the subsequent stadial. Available summer-temperature reconstructions for the mid- to late Eemian transition show decreasing values during that time. We present a new chironomid record from southern Germany that covers the mid-Eemian to the end of the first Würmian stadial ( c . 125-105 ka) and also parts of the late Rissian glaciation and early Brörup interstadial of the early Würmian glaciation. Based on this record we describe lake development in the former Füramoos palaeolake and quantitatively reconstruct July air temperature during the examined interval. Late Rissian sediments are dominated by two chironomid taxa, Sergentia coracina -type and Micropsectra radialis -type, indicating very cold conditions. Following an uncertain interval, probably including a hiatus at the late Rissian/Eemian transition, mid-Eemian sediments contain Tanytarsus glabrescens -type and Tanytarsus mendax -type suggesting relatively high July air temperatures. During the late Eemian, typically thermophilic taxa such as Tanytarsus glabrescens -type disappear, suggesting decreasing temperatures. Stadial A is associated with increases in Microtendipes pedellus -type suggesting more oligotrophic conditions. Early Brörup sediments contain Tanytarsus glabrescens -type, suggesting a slight increase in July air temperature. Reconstructed July air temperatures show temperatures of 7-8 °C during the late Rissian and a decline from ~15.5-12 °C during the mid- to late Eemian associated with decreasing Northern Hemisphere July insolation. July air temperature values vary between 12 and 14 °C in the late Eemian, while reconstructed temperatures remain within 12-13.5 °C during Stadial A. Our new chironomid-based temperature reconstruction provides valuable corroboration and new quantification of temperature development from the mid-Eemian to the early Brörup interstadial as well as for sections of the late Rissian from the alpine foreland of southern Germany

    The Constitutional Amending Process

    Get PDF
    Since the failure to ratify the Meech Lake Accord in June 1990, the constitutional future of Canada has been the topic of increasingly urgent debate. So far, a consensus has emerged on two things. First, federalism as it is enshrined in the Constitution Acts of 1867 and 1982 no longer meets the needs and aspirations of the majority. Second, the means used in the past to achieve major constitutional revision are no longer acceptable to the majority of Canadians. Put simply, constitutional revision is essential if Canada is to survive and the means of achieving this revision must be more open and more consultative in nature than in the past. We have not yet reached a consensus on issues of constitutional substance or form, including the form public input should take in the future. But one thing is clear: if an agreement is reached on changes to the Constitution, the issues of how these changes can be achieved under the existing amending process and how future amendments can be accomplished will have to be addressed. Attention will also have to be given to the formal amending procedure involving the rules for ratification and the informal procedure involving how proposals for amendment are formulated and initiated. To that end, the federal and provincial governments have been studying these various aspects of the amending process from initiation to ratification, past, present, and future. This report contributes to that undertaking

    Stable Biological Production in the Eastern Equatorial Pacific Across the Plio-Pleistocene Transition (∼3.35–2.0 Ma)

    Get PDF
    Upwelling within the Eastern Equatorial Pacific (EEP) Ocean is a key factor for the Earth's climate because it supports >10% of the present-day biological production. The dynamics of upwelling in the EEP across the Plio-Pleistocene transition—an interval particularly relevant for understanding near-future warming due to Anthropocene-like atmospheric carbon-dioxide levels—have been intensively studied for the region east of the East Pacific Rise. In contrast, changes of the equatorial upwelling regime in the open Pacific Ocean west of this oceanographic barrier have received markedly less attention. We therefore provide new proxy records from Ocean Drilling Program Site 849 located within the EEP open-ocean upwelling regime. Our target interval (∼3.35–2.0 Ma) covers the Plio-Pleistocene transition characterized by the intensification of Northern Hemisphere Glaciation (iNHG). We use benthic δ18O values to generate a new, high-resolution age model for Site 849, and sand-accumulation rates together with benthic δ13C values to evaluate net export production. Although showing temporary substantial glacial-interglacial variations, our records indicate stability in net export production on secular timescales across the iNHG. We suggest the following processes to have controlled the long-term evolution of primary productivity at Site 849. First, nutrient export from the high latitudes to the EEP; second, a successive shoaling of the Pacific nutricline during the studied interval; and third, a simultaneous reduction in dust-borne iron input.publishedVersio

    Reconciling the Greenland ice-core and radiocarbon timescales through the Laschamp geomagnetic excursion

    Get PDF
    Cosmogenic radionuclides, such as 10Be and 14C, share a common production signal, with their formation in the Earth's upper atmosphere modulated by changes to the geomagnetic field, as well as variations in the intensity of the solar wind. Here, we use this common production signal to compare between the radiocarbon (IntCal) and Greenland ice-core (GICC05) timescales, utilising the most pronounced cosmogenic production peak of the last 100,000 years – that associated with the Laschamp geomagnetic excursion circa 41,000 years ago. We present 54 new 14C measurements from a peat core (‘TP-2005’) from Tenaghi Philippon, NE Greece, contiguously spanning between circa 47,300 and 39,600 cal. BP, demonstrating a distinctive tripartite structure in the build up to the principal Laschamp production maximum that is not present in the consensus IntCal13 calibration curve. This is the first time that a continuous, non-reservoir corrected 14C dataset has been generated over such a long time span for this, the oldest portion of the radiocarbon timescale. This period is critical for both palaeoenvironmental and archaeological applications, with the replacement of Neanderthals by anatomically modern humans in Europe around this time. By placing our Tenaghi Philippon 14C dataset on to the Hulu Cave U-series timescale of Cheng et al. (2018) via Bayesian statistical modelling, the comparison of TP-2005 14C with Greenland 10Be fluxes also implicitly relates the underlying U-series and GICC05 timescales themselves. This comparison suggests that whilst these two timescales are broadly coherent, the IntCal13 timescale contains erroneous structure circa 40,000 cal. BP

    Sedimentological evidence for pronounced glacial‐interglacial climate fluctuations in NE Tibet in the latest Pliocene to early Pleistocene

    Get PDF
    The intensification of Northern Hemisphere glaciation (iNHG) and uplift of the Tibetan Plateau have been argued to be among the main drivers of climate change in midlatitude Central Asia during the Pliocene/Pleistocene. While most proxy records that support this hypothesis are from regions outside the Tibetan Plateau (such as from the Chinese Loess Plateau), detailed paleoclimatic information for the plateau itself during that time has yet remained elusive. Here we present a temporally highly resolved (~500 years) sedimentological record from the Qaidam Basin situated on the northeastern Tibetan Plateau that shows pronounced glacial‐interglacial climate variability during the interval from 2.7 to 2.1 Ma. Glacial (interglacial) intervals are generally characterized by coarser (finer) grain size, minima (maxima) in organic matter content, and maxima (minima) in carbonate content. Comparison of our results with Earth's orbital parameters and proxy records from the Chinese Loess Plateau suggests that the observed climate fluctuations were mainly driven by changes in the Siberian High/East Asian winter monsoon system as a response to the iNHG. They are further proposed to be enhanced by the topography of the Tibetan Plateau and its impact on the position and intensity of the westerlies

    Offshoring-Outsourcing and Onshoring Tradeoffs: The Impact of Coronavirus on Global Supply Chain

    Get PDF
    The world has become a global village with companies investing in different nations to remain afloat and competitive. In the process of offshoring- outsourcing, companies and nations have become interdependent in their efforts to bridge the supply chain network. However, during a pandemic, such as the Coronavirus (COVID-19) that involved the closure of borders, and during which there was a high demand of lifesaving machines and personal protective equipment, many countries were left scrambling for critical medical products such as ventilators and personal protective equipment for doctors. Hence, the tendency away from offshoring and outsourcing to onshoring production. COVID-19 has elicited that countries need to invest in an onshore business if they are to remain afloat. However, investing in onshore (local) business calls for a tradeoff, which some countries cannot afford. Many countries lack skilled labour (developing countries), and where available, it is too expensive (developed countries) making onshore an expensive venture. Besides, promoting manufacturing companies means increased air pollution and greenhouse gases that are responsible for 4.2–7.0 million premature deaths every year, and which costs $4.6 trillion per year. Such death rates and cost can hinder the onshore business. Therefore, for countries to survive in the era of a pandemic, the best alternative is to build strong ties with offshore-outsource nations

    Thermocline state change in the eastern equatorial Pacific during the late Pliocene/early Pleistocene intensification of Northern Hemisphere glaciation

    Get PDF
    The late Pliocene/early Pleistocene intensification of Northern Hemisphere glaciation (iNHG)  ∼ 2.5 million years ago (marine isotope stages, MIS, 100–96) stands out as an important tipping point in Earth's climate history, which strongly influenced oceanographic and climatic patterns including trade wind and upwelling strength in the eastern equatorial Pacific (EEP). The thermocline depth in the EEP, in turn, plays a pivotal role in the Earth's climate system: small changes in its depth associated with short-term climate phenomena such as the El Niño–Southern Oscillation can affect surface-water properties and the ocean–atmosphere exchange. However, thermocline dynamics in the EEP during the iNHG still remain unclear. While numerous studies have suggested a link between a thermocline shoaling in the EEP and Northern Hemisphere ice growth, other studies have indicated a stable thermocline depth during the iNHG; consequently, a causal relationship between thermocline dynamics and ice-sheet growth has been excluded. In light of these contradictory views, we have generated geochemical (planktic foraminiferal δ18O, δ13C and Mg&thinsp;∕&thinsp;Ca), sedimentological (sand accumulation rates) and faunal (abundance data of thermocline-dwelling foraminifera) records for Ocean Drilling Program Site 849 located in the central region of the EEP. Our records span the interval from  ∼ 2.75 to 2.4&thinsp;Ma (MIS G7–95), which is critical for understanding thermocline dynamics during the final phase of the iNHG. Our new records document a thermocline shoaling from  ∼ 2.64 to 2.55&thinsp;Ma (MIS G2–101) and a relatively shallow thermocline from  ∼ 2.55&thinsp;Ma onwards (MIS 101–95). This indicates a state change in thermocline depth at Site 849 shortly before the final phase of the iNHG. Ultimately, our data support the hypothesis that (sub-)tropical thermocline shoaling may have contributed to the development of large Northern Hemisphere ice sheets.</p

    Sediment history mirrors Pleistocene aridification in the Gobi Desert (Ejina Basin, NW China)

    Get PDF
    Central Asia is a large-scale source of dust transport, but it also held a prominent changing hydrological system during the Quaternary. A 223 m long sediment core (GN200) was recovered from the Ejina Basin (synonymously Gaxun Nur Basin) in NW China to reconstruct the main modes of water availability in the area during the Quaternary. The core was drilled from the Heihe alluvial fan, one of the world's largest alluvial fans, which covers a part of the Gobi Desert. Grain-size distributions supported by endmember modelling analyses, geochemical-mineralogical compositions (based on XRF and XRD measurements), and bioindicator data (ostracods, gastropods, pollen and non-pollen palynomorphs, and n-alkanes with leaf-wax delta D) are used to infer the main transport processes and related environmental changes during the Pleistocene. Magnetostratigraphy supported by radionuclide dating provides the age model. Grain- size endmembers indicate that lake, playa (sheetflood), fluvial, and aeolian dynamics are the major factors influencing sedimentation in the Ejina Basin. Core GN200 reached the pre-Quatemary quartz- and plagioclase-rich "Red Clay" formation and reworked material derived from it in the core bottom. This part is overlain by silt-dominated sediments between 217 and 110 m core depth, which represent a period of lacustrine and playa-lacustrine sedimentation that presumably formed within an endorheic basin. The upper core half between 110 and 0 m is composed of mainly silty to sandy sediments derived from the Heihe that have accumulated in a giant sediment fan until modem time. Apart from the transition from a siltier to a sandier environment with frequent switches between sediment types upcore, the clay mineral fraction is indicative of different environments. Mixed-layer clay minerals (chlorite/smectite) are increased in the basal Red Clay and reworked sediments, smectite is indicative of lacustrine-playa deposits, and increased chlorite content is characteristic of the Heihe river deposits. The sediment succession in core GN200 based on the detrital proxy interpretation demonstrates that lake-playa sedimentation in the Ejina Basin has been disrupted likely due to tectonic events in the southern part of the catchment around 1 Ma. At this time Heihe broke through from the Hexi Corridor through the Heli Shan ridge into the northern Ejina Basin. This initiated the alluvial fan progradation into the Ejina Basin. Presently the sediment bulge repels the diminishing lacustrine environment further north. In this sense, the uplift of the hinterland served as a tipping element that triggered landscape transformation in the northern Tibetan foreland (i.e. the Hexi Corridor) and further on in the adjacent northern intracontinental Ejina Basin. The onset of alluvial fan formation coincides with increased sedimentation rates on the Chinese Loess Plateau, suggesting that the Heihe alluvial fan may have served as a prominent upwind sediment source for it
    corecore