Knowledge rationales in human geography: Economic,policy, empowerment,and methodological

The article presents a systematic review of 152 articles in which the concept of knowledge is applied and that are published in international human geography journals. As the importance of knowledge in society is increasing, especially economic geography has taken up the task of reviewing the concept or role of knowledge in geography. However, there is a need for a more nuanced understanding of knowledge in economic geography, drawing more broadly on human geographical research. The authors analyse how the concept of knowledge is understood and applied in contemporary human geography. Their results demonstrate four knowledge rationales: economic, policy, empowerment, and methodological. Each rationale and their combinations display a particular role and purpose for knowledge, as well as a distinct approach to space. Separately, each rationale provides several insights into a more nuanced understanding of specific aspects of knowledge. When combined, the four rationales offer a holistic overview of the field. The authors conclude that the empowerment rationale offers novel methodological choices towards a more nuanced understanding of knowledge in economic geography.     

Health and environmental co-benefits and conflicts of actions to meet UK carbon targets

Many actions to reduce GHG emissions have wider impacts on health, the economy, and the environment, beyond their role in mitigating climate change. These ancillary impacts can be positive (co-benefits) or negative (conflicts). This article presents the first quantitative review of the wider impacts on health and the environment likely to arise from action to meet the UK's legally-binding carbon budgets. Impacts were assessed for climate measures directed at power generation, energy use in buildings, and industry, transport, and agriculture. The study considered a wide range of health and environmental impacts including air pollution, noise, the upstream impacts of fuel extraction, and the lifestyle benefits of active travel. It was not possible to quantify all impacts, but for those that were monetized the co-benefits of climate action (i.e. excluding climate benefits) significantly outweigh the negative impacts, with a net present value of more than £85 billion from 2008 to 2030. Substantial benefits arise from reduced congestion, pollution, noise, and road accidents as a result of avoided journeys. There is also a large health benefit as a result of increased exercise from walking and cycling instead of driving. Awareness of these benefits could strengthen the case for more ambitious climate mitigation action.

Policy relevance

This article demonstrates that actions to mitigate GHG emissions have significant wider benefits for health and the environment. Including these impacts in cost–benefit analysis would strengthen the case for the UK (and similar countries) to set ambitious emissions reduction targets. Understanding co-benefits and trade-offs will also improve coordination across policy areas and cut costs. In addition, co-benefits such as air quality improvements are often immediate and local, whereas climate benefits may occur on a longer timescale and mainly in a distant region, as well as being harder to demonstrate. Dissemination of the benefits, along with better anticipation of trade-offs, could therefore boost public support for climate action.     

Weichselian history of the Fennoscandian ice sheet in southern Sweden and the southwestern Baltic Basin

This study presents the Weichselian stratigraphy on Kriegers Flak in the southwestern Baltic Sea, and correlates it to new sections in southernmost Sweden and to previously published stratigraphic sequences from SW Skåne. A total of four Weichselian advances are identified based on our correlations. The oldest till, observed only on Kriegers Flak, is dated to the Early or Middle Weichselian and tentatively correlated to the Ristinge advance, previously identified in Denmark. It is overlain by three interstadial sediment units, starting with brackish clay and followed by terrestrial and lacustrine deposits, which have been dated to 42–36 ka, and finally by glaciolacustrine clay dated to 28.5–26 ka. After 30 ka, the Fennoscandian ice sheet advanced through the Baltic Basin and into the coastal areas of southernmost Sweden where the Allarp Till was deposited, followed by a deglaciation sequence. The uppermost tills, the Dalby Till and the Lund till, were deposited during the LGM advance and the subsequent re‐advances through the Baltic Basin. Based on the new evidence it has been possible to identify and date a Middle and Late Weichselian till succession in southern Sweden and provide a strong correlation to the established glacial stratigraphies in Sweden and Denmark.     

Peering inside the peak ring of the Chicxulub Impact Crater—its nature and formation mechanism

The IODP‐ICDP Expedition 364 drilled into the Chicxulub crater, peering inside its well‐preserved peak ring. The borehole penetrated a sequence of post‐impact carbonates and a unit of suevites and clast‐poor impact melt rock at the top of the peak ring. Beneath this sequence, basement rocks cut by pre‐impact and impact dykes, with breccias and melt, were encountered at shallow depths. The basement rocks are fractured, shocked and uplifted, consistent with dynamic collapse, uplift and long‐distance transport of weakened material during collapse of the transient cavity and final crater formation.     

Diffusion,degradation or on-site stabilisation – Identifying causes of kinetic processes involved in metal–humate complexation

The applicability of equilibrium models for humic-bound transport of toxic or radioactive metals is affected by kinetic processes leading to an increasing inertness of metal–humic complexes. The chemical background is not yet understood. It is widely believed that bound metals undergo an in-diffusion process within the humic colloids, changing from weaker to stronger binding sites. This work is focussed on the competition effect of Al(III) on complexation of Tb(III) or Eu(III) as analogues of trivalent actinides. By using ion exchange and spectroscopic methods, their bound fractions were determined for solutions of Al and humic acid that had been pre-equilibrated for different periods of time. Whilst the amount of bound Al remained unchanged, its blocking effect was found to increase over a time frame of 2 days, which corresponds to the kinetics of the increase in complex inertness reported in most pertinent studies. Thus, the derived “diffusion theory” turned out to be inapplicable, since it cannot explain an increase in competition for the “initial” sites. A delayed degradation of polynuclear species (as found for Fe) does not occur. Consequently, the temporal changes must be based on structural rearrangements in the vicinity of bound Al, complicating the exchange or access. Time-dependent studies by laser fluorescence spectroscopy (steady-state and time-resolved) yielded evidence of substantial alterations, which were, however, immediately induced and did not show any significant trend on the time scale of interest, suggesting that the stabilisation process is based on comparatively moderate changes.     

Microscale oxygen isotope variations in 1.9 Ga Gunflint cherts: Assessments of diagenesis effects and implications for oceanic paleotemperature reconstructions

Variations in the oxygen isotope composition (δ¹⁸O) of five cherts from the 1.9 Ga Gunflint iron formation (Canada) were studied at the micrometer scale by ion microprobe to try to better understand the processes that control δ¹⁸O values in cherts and to improve seawater paleotemperature reconstructions. Gunflint cherts show clearly different δ¹⁸O values for different types of silica with for instance a difference of ≈15‰ between detrital quartz and microquartz. Microquartz in the five samples is characterized by large intra sample variations in δ¹⁸O values, (δ¹⁸O of quartz varies from 4.6‰ to 6.6‰ at the 20 μm scale and from ≈12‰ to 14‰ at 2 μm scale). Isotopic profiles in microquartz adjacent to hydrothermal quartz veins demonstrate that microquartz more than ≈200 μm away from the veins has preserved its original δ¹⁸O value.At the micrometer spatial resolution of the ion probe, data reveal that microquartz has preserved a considerable δ¹⁸O heterogeneity that must be regarded as a signature inherited from its diagenetic history. Modelling of the δ¹⁸O variations produced during the diagenetic transformation of sedimentary amorphous silica precursors into microquartz allows us to calculate seawater temperature (T_sw at which the amorphous silica precipitated) and diagenesis temperature (T_diagenesis at which microquartz formed) that reproduce the δ¹⁸O distributions (mean, range and shape) measured at micrometer scale in microquartz. The two critical parameters in this modelling are the δ¹⁸O value and the mass fraction of the diagenetic fluid. Under these assumptions, the most likely ranges for T_sw and T_diagenesis are from 37 to 52 °C and from 130 to 170 °C, respectively.     

Deep alpine valleys: examples of geophysical explorations in Austria

Results from geophysical explorations of three deep valleys, selected from different tectonic regimes in the Eastern Alps (Ötz-, Oichten-, and Drau Valley), are presented and discussed. Ongoing tectonic deformation may use tectonic structures related to these valleys. However, seismic activity is low there. During the Würm ice age, the thickness of the ice cover ranged between 300 and 1,500 m above present ground elevation. The geophysical investigations comprised reflection seismology, gravity- and resistivity surveys. The maximum depth down to the erosional base of the valleys varies from ~340 to 700 m. Distinct layer packages of the valley-infill at depths greater than 250 m were termed “old valley-fill”. Geophysical parameters and a comparison with the reflection seismic image of an intermediate layer at the recent Pasterze glacier suggest that the top of the “old valley-fill” represents the glacier bed during the decay of the Würm glaciation. Deep erosion is not related to high basal shear stress. The confluence of tributary glaciers is apparently not a significant factor for deep erosion in our examples of deep alpine valleys. We conclude that deep erosion may be related to high water pressure at the glacier bed, supported by specific processes of tectonic weakening.