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| 2. |
- Barbieri, Maurizio, et al.
(författare)
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Changes in groundwater trace element concentrations before seismic and volcanic activities in Iceland during 2010-2018
- 2021
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697 .- 1879-1026. ; 793
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Tidskriftsartikel (refereegranskat)abstract
- We analysed temporal variations of trace element concentrations in groundwater from a 101 m-deep borehole (HA01) in northern Iceland during 2010–2018 and compared them with seismic and volcanic events that occurred in the same period to identify potential hydrogeochemical precursors. An increase of B, Al, V, Li and Mo concentrations started from eight months to one month before the 2014 Bárðarbunga eruption (~115 km from HA01), a major rifting event in central Iceland, while Ga and V concentrations began to increase one day and one month after the onset of the event, respectively. We also found that concentrations of some trace elements (Li, B, Ga, Mo, Sr, Rb and Fe) significantly increased before an Mw 5.0 earthquake that occurred ~80 km from the borehole in 2018. However, other notable hydrogeochemical changes were detected during the monitoring period without apparent correlation with the seismic and volcanic events in the region. This study shows that the systematic long-term hydrogeochemical monitoring in seismic and volcanic areas is critical to advance the science of seismic and eruptive precursors. Furthermore, the use of statistical tools, such as Principal Component Analysis (PCA) and Change Point (CP) detection can help identify the most useful chemical elements and validate the trend variability of those elements in the time series, reducing arbitrary choices of pre-seismic and pre-volcanic hydrogeochemical anomalies as potential precursors.
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| 3. |
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| 4. |
- Boschetti, Tiziano, et al.
(författare)
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Geothermometry and water-rock interaction modelling at Hafralækur : Possible implications of temperature and CO2 on hydrogeochemical changes previously linked to earthquakes in northern Iceland
- 2022
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Ingår i: Geothermics. - : Elsevier BV. - 0375-6505 .- 1879-3576. ; 105
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Tidskriftsartikel (refereegranskat)abstract
- The low enthalpy (T < 150 °C) groundwater in the HA01 borehole at Hafralækur has a long time series (2008–2018) of chemical and isotopic data. In the previous studies, the variations in chemical and isotope parameters were statistically related to seismic activity. However, the possible effect of temperature has not yet been evaluated. To fill this gap, the results obtained from the classical geothermometric equations (silica solid phases, Na/K, Na-K-Ca) were compared. However, considering that the use of classical geothermometry using the Na/K ratio or silica solid phases solubility is limited by the presence of clay minerals and alkaline conditions (i.e., the presence of pH-dependant silicate anions), new equilibria reactions between labradorite, zeolites (analcime, stilbite) and the activity of the dissolved species in the fluid are presented to overcome this problem. In addition, kinetic reaction path models are presented to trace the possible role of both temperature and CO2 during the most evident chemical variations during earthquakes.
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| 5. |
- Fru, Ernest Chi, et al.
(författare)
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Transient fertilization of a post-Sturtian Snowball ocean margin with dissolved phosphate by clay minerals
- 2023
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Ingår i: Nature Communications. - 2041-1723. ; 14:1
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Tidskriftsartikel (refereegranskat)abstract
- Marine sedimentary rocks deposited across the Neoproterozoic Cryogenian Snowball interval, similar to 720-635 million years ago, suggest that post-Snowball fertilization of shallow continental margin seawater with phosphorus accelerated marine primary productivity, ocean-atmosphere oxygenation, and ultimately the rise of animals. However, the mechanisms that sourced and delivered bioavailable phosphate from land to the ocean are not fully understood. Here we demonstrate a causal relationship between clay mineral production by the melting Sturtian Snowball ice sheets and a short-lived increase in seawater phosphate bioavailability by at least 20-fold and oxygenation of an immediate post-Sturtian Snowball ocean margin. Bulk primary sediment inputs and inferred dissolved seawater phosphate dynamics point to a relatively low marine phosphate inventory that limited marine primary productivity and seawater oxygenation before the Sturtian glaciation, and again in the later stages of the succeeding interglacial greenhouse interval.
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| 6. |
- Gerhardt, Karin, et al.
(författare)
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Nog nu, politiker – ta klimatkrisen på allvar : 1 944 svenska forskare och anställda i forskarvärlden: Vad är det ni inte förstår?
- 2022
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Ingår i: Aftonbladet. - 1103-9000. ; :2022-08-25
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Tidskriftsartikel (populärvet., debatt m.m.)abstract
- DEBATT. Som forskare och medborgare är vi arga och förtvivlade över den senaste tidens utveckling. Vi ser hur en majoritet av våra politiska partier överger klimatpolitiken och i stället föreslår eller genomför politik som går stick i stäv med Parisavtalet och Sveriges klimat- och miljömål.Våra politiker måste ta krisen på allvar och leda omställningen till ett framtida samhälle inom planetens gränser. Forskningen visar att en sådan framtid är möjlig. Det skriver 1 944 forskare och anställda från 45 svenska lärosäten och forskningsinstitut.
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| 7. |
- Kylander, Malin E., et al.
(författare)
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It's in your glass : a history of sea level and storminess from the Laphroaig bog, Islay (southwestern Scotland)
- 2020
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Ingår i: Boreas. - : Wiley. - 0300-9483 .- 1502-3885. ; 49:1, s. 152-167
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Tidskriftsartikel (refereegranskat)abstract
- Severe winter windstorms have become an increasingly common occurrence over recent decades in northwestern Europe. Although there exists considerable uncertainty, storminess is projected to increase in the future. On centennial to millennial time scales in particular, the mechanisms forcing storminess remain unsettled. We contribute to available palaeostorm records by reconstructing changes over the last 6670 years using a coastal peat sequence retrieved from the ombrotrophic Laphroaig bog on Islay, southwestern Scotland. We use a combination of ash content, grain size and elemental chemistry to identify periods of greater storminess, which are dated to 6605, 6290-6225, 5315-5085, 4505, 3900-3635, 3310-3130, 2920-2380, 2275-2190, 2005-1860, 1305-1090, 805-435 and 275 cal. a BP. Storm signals in the first half of the record up to similar to 3000 cal. a BP are mainly apparent in the grain-size changes. Samples from this time period also have a different elemental signature than those later in the record. We speculate that this is due to receding sea levels and the consequent establishment of a new sand source in the form of dunes, which are still present today. The most significant events and strongest winds are found during the Iron Ages Cold Epoch (2645 cal. a BP), the transition into, and in the middle of, the Roman Ages Warm Period (2235 and 1965 cal. a BP) and early in the Little Ice Age (545 cal. a BP). The Laphroaig record generally agrees with regionally relevant peat palaeostorm records from Wales and the Outer Hebrides, although the relative importance of the different storm periods is not the same. In general, stormier periods are coeval with cold periods in the region as evidenced by parallels with increased ice-rafted debris in the North Atlantic, highlighting that sea-ice conditions could impact future storminess and storm track position.
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| 8. |
- Nicholas, Kimberly, et al.
(författare)
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Analys av sju riksdagspartiers klimatpolitik utförd av klimat- och omställningsforskare : Sveriges klimatpolitik inför riksdagsvalet 2022 enligt Researchers’ Desk
- 2022
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Rapport (populärvet., debatt m.m.)abstract
- ● Syftet med denna rapport är att ge forskares analys av riksdagspartiernas klimatpolitik inför valet 2022.● Alla som har bidragit till denna rapport är klimat- eller omställningsforskare och medlemmar i Researchers’ Desk1.● Researchers’ Desk är en oberoende, ideell organisation, med över 80 ledande forskare i Sverige, som arbetar med olika aspekter av klimatförändringarna.● Alla de åtta politiska partierna tillfrågades om att besvara en enkät med frågor om sina klimatmål och sin politik. Moderaterna avböjde att delta i undersökningen. De övriga sju partierna svarade med varierande grad av utförlighet.● Författarna av denna rapport har använt partiernas svar som underlag för sin kvalitativa analys och bedömning.● Vår granskning har fokuserat på förslagens ambitionsnivå, potential, realism och problem i relation till befintlig forskning.● Tidigare publicerat genom detta projekt:○ Mål för territoriella utsläpp, av Alasdair Skelton, Paul Glantz, och KimberlyNicholas○ Mål för LULUCF-sektorn, av Erik Pihl, Åsa Kasimir, och Peter Roberntz
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| 9. |
- Niemi, Maria, et al.
(författare)
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Lockdown Measures Which Reduced Greenhouse Gas Emissions With Little Negative Impact on Quality of Life
- 2021
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Ingår i: Earth's Future. - 2328-4277. ; 9:5
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Tidskriftsartikel (refereegranskat)abstract
- Lockdown measures in response to the new Covid-19 virus have caused the largest ever fall of annual greenhouse gas emissions. A key question that we attempt to answer in this study is which, if any, of these measures can be productively encouraged post-lockdown in efforts to sustain at least part of this reduction in emissions. Sweden is uniquely suited for our study because the voluntary nature of lockdown in Sweden allowed us to assess the level of compliance to recommendations and its effects on greenhouse gas emissions. First, we assessed the change of perceived quality of life (QOL) among 746 individuals from Stockholm region due to adhering to lockdown measures. Second, we calculated the associated change of annual per capita greenhouse emissions. We found that avoiding travel for work, avoiding purchasing, and avoiding restaurants had the least negative effect on QOL, and at the same time the largest positive effect on carbon dioxide equivalent (CO(2)e) emission reductions. We conclude that these are potential leverage points for stimulating behavioral change that has a positive climatic impact.
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| 10. |
- Nosenzo, Francesco, 1993-
(författare)
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Chemical and isotopic records of polycyclic histories in a subducted continental crust (Dora-Maira Massif, Western Alps)
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- At convergent plate margin, part of the continental crust can be subducted and exhumed. During continental subduction a pre-existing crust is reworked. Remnants of an older orogen are recycled and subjected to (ultra)-high-pressure metamorphism. During subduction, polycyclic rocks undertake a second metamorphic cycle, whereas monocyclic rocks are metamorphosed for the first time. In reworked rocks the pre-subduction record is overprinted and partially or completely lost. Despite this difficulty, reconstructing the pre-subduction history of the recycled crust is crucial, because pre-subduction characters (such as H2O content) can strongly influence how rocks respond to reworking during subduction.The Dora-Maira Massif is worldwide renowned as a (ultra)-high-pressure continental terrane. However, its northern part remained essentially unexplored in recent times. In this thesis work the northern Dora-Maira Massif is used as a case study to investigate recycling of continental crust. The aim is to constrain what type of crust is subducted and exhumed and to unravel the role of fluids during subduction of polycyclic material. Field work, petrology, thermodynamic modelling and geochronology are integrated.New field and geochronological evidence indicate that the northern Dora-Maira Massif displays an internal architecture more complex than what previously thought. It is subdivided in several tectonic units likewise the southern Dora-Maira Massif. Chemical and isotopic records of the reworked rocks reveal a pre-Alpine history spanning from the Lower Palaeozoic to the Mesozoic. A polycyclic basement preserves relicts of a pre-Alpine Barrovian metamorphism connected with the Variscan orogenesis. The absence of granulite-facies partially molten pre-Alpine rocks indicates that only the upper crust was reworked in the Dora-Maira Massif.Thermodynamic modelling indicates that polycyclic micaschists were rehydrated between the Variscan and the Alpine peak metamorphism. Polycyclic garnet texture and chemistry and metamorphic zircon record a main episode of fluid infiltration at the end of the Variscan cycle and not during the Alpine cycle. Pre-Alpine re-hydration of the upper crust allowed high-pressure re-equilibration during subduction.
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