Preface

In this special issue of GEUS Bulletin, the many riddles regarding the platinum group elements and gold (PGE-Au) mineralisation of the East Greenland Skaergaard intrusion are untangled and discussed. The Skaergard PGE-Au mineralisation, as defined in this study, embodies an enigmatic and rich ore-formation that arguably could have been an economic resource, had it not been for its ice-locked position in central East Greenland. The authors of this study (Rudashevsky et al. 2023, this volume) characterise the systematic variability in the precious metal mineralogy from the contact towards the interior of the intrusion based on the analysis of more than 4000 individual PGE-Au grains. This variability is interpreted in the light of 90 years of research and over 1000 publications pertaining to magma chamber processes in the Skaergaard intrusion.  With such an impressive library of knowledge, on a comparatively simple magmatic system such as the Skaergard intrusion, we should have discovered a few islands of truth in igneous petrology and ore-deposit formation. And indeed, we have. But we are also enriched with an evolving story, where answering one question only serves to raise three new questions.  This study demonstrates the variability of PGE-Au phases throughout the ore-forming zone of the Skaergaard intrusion. As previously observed, PGE-Au mineralisation in the central parts is divided into several layers over 30–40 m of the cumulus stratigraphy with increasing Pd/Pt ratios upwards, an Au-rich upper part and a low sulphide content throughout all layers. Close to the contact the precious metal zonation is less pronounced, and it is significantly more sulphide rich. The PGE mineralogy deviates significantly from the centre to the margin. These complex lateral and vertical variations cannot be explained by one genetic model but require an intricate combination of igneous processes including silicate-melt liquid immiscibility, sulphide-melt immiscibility, sulphide-melt resorptions, precious metal transport by volatile-rich fluids and, finally, the solidification rate of the cumulus mushes.  For other well-preserved PGE-Au deposits throughout the world, we observe a great variation of ore-forming models. Remarkably, most of these models may be applied to various parts of the Skaergaard mineralisation. The authors suggest that the Skaergaard intrusion preserves different steps in PGE-Au ore-genesis which, in many other intrusions are obliterated by later igneous events. Therefore, the legacy of the Skaergaard mineralisation is the preservation of igneous ore-forming events that may also precede the genesis of other PGE-Au deposits in the world. After the last conclusion, I guarantee that you will be confused and perhaps a bit triggered but hopefully also inspired and bursting with new questions on the genesis of PGE-Au deposits in mafic and ultramafic igneous complexes. In light of the recent study, you may even be encouraged to look at your favourite PGE-Au deposit with fresh eyes. This study beautifully demonstrates that turning the next page in the book of magma chamber processes is more important than seeing ‘The End’

An urban consolidation center in the city of Copenhagen: a simulation study

Urban consolidation centers (UCCs) have a key role in many initiatives in urban logistics, yet few of them are successful in the long run. The high costs have proven a barrier that prevents attracting a sufficient high number of UCC users. In this paper, we study how the user base of a UCC develops under a variety of administrative policies. We perform an agent-based simulation applied to the city of Copenhagen, making use of its real street network and retailer locations. We collect data from a variety of sources to help modeling the agents. Both the data and case setup are validated by means of expert interviews. We test 1,458 schemes that combine several administrative measures and cost settings. The numerical results indicate that most schemes yield significant environmental benefits; many of them are able to reduce the truck kilometers driven by about 65% and emissions by about 70%. The key challenge isto identify schemes that are also financially sustainable. We show that it is essential for the UCC to ensure the commitment of carriers as soon as possible, as the bulk of the revenue can be generated from this target group. Subsequent revenues may be generated by offering value-adding services to receivers. Based on the numerical experiments, we pose various propositions that aid in providing favorable conditions for a UCC, improving its chances of long-term success

Hæren i sikkerhetspolitiske kriser: hvor relevant?

Denne studien omhandler Hærens forberedelser for en sikkerhetspolitisk krise, med vekt på utdanning, øving og trening i Hærens taktiske avdelinger. Studien vil først etablere en forståelse av hva en krise er, og hvordan norske myndigheter vil håndtere en krise. Krisehåndteringen nasjonalt setter rammebetingelsene for hvordan Hæren som del av Forsvaret er forventet å bidra i krisehåndteringen. Nasjonale myndigheter bygger sin krisehåndtering på fire prinsipper. Dette er ansvars-, nærhet-, likhet- og samvirkeprinsippet. Disse prinsippene gjelder for det strategiske nivået i håndteringen av kriser generelt. De er ikke like anvendbare for det taktiske nivået i Hærens involvering og håndtering av den samme krisesituasjonen. Hæren er en del av de sentrale myndighetenes apparat for å gjennomføre en god krisehåndtering i en sikkerhetspolitisk krise. Studien ser på hvilke prinsipper som kan anvendes for å definere hvordan Hærens forberedelser bør gjennomføres for å sikre ivaretagelse av myndighetenes målsetning i den aktuelle håndteringen av en sikkerhetspolitisk krise. De prinsippene denne studien har valgt å legge til grunn er evne til å forsvare nasjonale interesser, evne til å forhindre en uønsket opptrapping, og evne til å være forberedt på en mulig opptrapping av krisen. Disse prinsippene benyttes til å analysere Hærens forberedelser for å håndtere en sikkerhetspolitisk krise. Analysen vil ta for seg Hæren i to søyler. Den første søylen er kompetansesøylen, som er definert som Krigsskolen og Hærens Våpenskole. Søyle to, den operative søylen, består av Brigade Nord, Garnisonen i Sør-Varanger og Hans Majestets Kongens Garde. Sett opp mot de tre prinsippene lagt til grunn for den taktiske forberedelsen for en sikkerhetspolitisk krise, kan det se ut som Hæren vektlegger i stor grad vektlegger sine forberedelser mot det som er definert som den dimensjonerende oppgaven. Den dimensjonerende oppgaven er høyintensive, offensive operasjoner i brigaderammen. Dette betyr at krisehåndtering som et eget emne prioriteres i liten grad. De forberedelsene som gir effekt mot krisehåndtering, fokuseres i stor grad mot avskrekking, mens evnen til å forhindre en uønsket opptrapping synes svært lite vektlagt i den utdanning, trening og øving som Hæren gjennomfører. Beroligelse av en motpart er i Hæren ikke en oppgave som gis oppmerksomhet i forberedelsene

Impact of travel time uncertainties on the solution cost of a two-echelon vehicle routing problem with synchronization

Two-echelon vehicle routing problems which contain synchronization between vehicles can be deeply impacted by time uncertainty, because one vehicle's delay can propagate to other vehicles. In this paper, we evaluate the deterministic solution of such a problem based on simulated travel time scenarios. The information obtained by simulation is incorporated in the optimization procedure iteratively. Computational results show that the degree of synchronization in an instance is directly correlated with the potential improvements by reoptimization. We present findings on the number of travel time scenarios required to obtain a representative picture of the stochastic solutions. In addition, we demonstrate that time dependent travel times can be aggregated on a city-wide level and linearized as a function of free flow times without major loss of reliability

An urban consolidation center in the city of Copenhagen

Urban consolidation centers (UCCs) have a key role in many initiatives in urban logistics, yet few of them are successful in the long run. The high costs have proven a barrier that prevents attracting a sufficient high number of UCC users. In this paper, we study how the user base of a UCC develops under a variety of administrative policies. We perform an agent-based simulation applied to the city of Copenhagen, making use of its real street network and retailer locations. We collect data from a variety of sources to help modeling the agents. Both the data and case setup are validated by means of expert interviews. We test 1,458 schemes that combine several administrative measures and cost settings. The numerical results indicate that most schemes yield significant environmental benefits; many of them are able to reduce the truck kilometers driven by about 65% and emissions by about 70%. The key challenge isto identify schemes that are also financially sustainable. We show that it is essential for the UCC to ensure the commitment of carriers as soon as possible, as the bulk of the revenue can be generated from this target group. Subsequent revenues may be generated by offering value-adding services to receivers. Based on the numerical experiments, we pose various propositions that aid in providing favorable conditions for a UCC, improving its chances of long-term success. Document type: Articl

Experiments with remote sensing in the context of avalanche warning and detection

In Proceedings of Advances in Avalanche Forecasting, Podbanské, Slovakia, 22 October 2012Two Norwegian projects carried out by NGI and NR have investigated and experimented with the potential of using remote sensing for avalanche warning and detection: The Norwegian Space Centre (NSC) supported project “Improved Avalanche Warning Using Satellite Data” (2008-2010) and the European Space Agency (ESA) funded project “Avalanche Inventory for Decision Support and Hind-cast - AvalRS” (2008–2011)