Henrik Hovland Svensen

• Deegan, Frances M.; Callegaro, Sara; Davies, Joshua H.F.L. & Svensen, Henrik Hovland (2023). Driving Global Change One LIP at a Time. Elements. ISSN 1811-5209. 19(5), p. 269–275. doi: 10.2138/gselements.19.5.269.
• Svensen, Henrik Hovland; Jones, Morgan Thomas & Mather, Tamsin A. (2023). Large Igneous Provinces and the Release of Thermogenic Volatiles from Sedimentary Basins. Elements. ISSN 1811-5209. 19(5), p. 282–288. doi: 10.2138/gselements.19.5.282.
• Berndt, Christian; Planke, Sverre; Alvarez Zarikian, Carlos A.; Frieling, Joost; Jones, Morgan Thomas & Millett, John M. [Show all 36 contributors for this article] (2023). Shallow-water hydrothermal venting linked to the Palaeocene–Eocene Thermal Maximum. Nature Geoscience. ISSN 1752-0894. 16, p. 803–809. doi: 10.1038/s41561-023-01246-8. Full text in Research Archive Show summary

  The Palaeocene–Eocene Thermal Maximum (PETM) was a global warming event of 5–6 °C around 56 million years ago caused by input of carbon into the ocean and atmosphere. Hydrothermal venting of greenhouse gases produced in contact aureoles surrounding magmatic intrusions in the North Atlantic Igneous Province have been proposed to play a key role in the PETM carbon-cycle perturbation, but the precise timing, magnitude and climatic impact of such venting remains uncertain. Here we present seismic data and the results of a five-borehole transect sampling the crater of a hydrothermal vent complex in the Northeast Atlantic. Stable carbon isotope stratigraphy and dinoflagellate cyst biostratigraphy reveal a negative carbon isotope excursion coincident with the appearance of the index taxon Apectodinium augustum in the vent crater, firmly tying the infill to the PETM. The shape of the crater and stratified sediments suggests large-scale explosive gas release during the initial phase of vent formation followed by rapid, but largely undisturbed, diatomite-rich infill. Moreover, we show that these vents erupted in very shallow water across the North Atlantic Igneous Province, such that volatile emissions would have entered the atmosphere almost directly without oxidation to CO2 and at the onset of the PETM.

• Svensen, Henrik Hovland; Jones, Morgan Thomas; Percival, Lawrence; Grasby, Stephen E. & Mather, Tamsin (2023). Release of mercury during contact metamorphism of shale: Implications for understanding the impacts of large igneous province volcanism. Earth and Planetary Science Letters. ISSN 0012-821X. 619. doi: 10.1016/j.epsl.2023.118306. Full text in Research Archive
• Jones, Morgan Thomas; Stokke, Ella Wulfsberg; Rooney, Alan D.; Frieling, Joost; Pogge von Strandmann, Philip A. E. & Wilson, David J. D. [Show all 15 contributors for this article] (2023). Tracing North Atlantic volcanism and seaway connectivity across the Paleocene-Eocene Thermal Maximum (PETM). Climate of the Past. ISSN 1814-9324. 19(8), p. 1623–1652. doi: 10.5194/cp-19-1623-2023. Full text in Research Archive
• Deegan, Frances M.; Bédard, Jean H.; Grasby, Stephen E.; Dewing, Keith; Geiger, Harri & Misiti, Valeria [Show all 13 contributors for this article] (2022). Magma-Shale Interaction in Large Igneous Provinces: Implications for Climate Warming and Sulfide Genesis. Journal of Petrology. ISSN 0022-3530. 63(9), p. 1–10. doi: 10.1093/petrology/egac094. Full text in Research Archive Show summary

  Large Igneous Provinces (LIPs) whose magma plumbing systems intersect sedimentary basins are linked to upheavals of Earth’s carbon and sulfur cycles and thus climate and life history. However, the underlying mechanistic links between these phenomena are elusive. We address this knowledge gap through short time-scale petrological experiments (1200 °C and 150 MPa) that explore interaction between basaltic melt and carbonaceous shale (mudstone) using starting materials from the Canadian High Arctic LIP and the Sverdrup Basin in which it intrudes. Here we show that entrainment of shale xenoliths in basaltic melt causes shale to shatter due to incipient thermal stress and devolatilization, which accelerates assimilation by increasing reactive surface area. Shale assimilation therefore facilitates transfer of sediment-derived volatile elements to the shallow parts of LIP plumbing systems, whereupon carbon dominates the vapor phase whilst sulfur is partitioned into sulfide melt droplets. This study reveals that although carbon and sulfur are efficiently mobilized as a consequence of shale assimilation, sulfides can sequester sulfur - an important climate cooling agent - thus enhancing net emissions of climate warming greenhouse gases by shale-intersecting LIPs.

• Shen, Jun; Yin, Runsheng; Algeo, Thomas J.; Svensen, Henrik Hovland & Schoepfer, Shane D. (2022). Mercury evidence for combustion of organic-rich sediments during the end-Triassic crisis. Nature Communications. ISSN 2041-1723. 13. doi: 10.1038/s41467-022-28891-8. Full text in Research Archive
• Bajard, Manon Juliette Andree; Ballo, Eirik Gottschalk; Høeg, Helge Irgens; Bakke, Jostein; Støren, Eivind Wilhelm Nagel & Loftsgarden, Kjetil [Show all 11 contributors for this article] (2022). Climate adaptation of pre-Viking societies. Quaternary Science Reviews. ISSN 0277-3791. 278. doi: 10.1016/j.quascirev.2022.107374. Full text in Research Archive Show summary

  Understanding how the Viking societies were impacted by past climate variability and how they adapted to it has hardly been investigated. Here, we have carried out a new multi-proxy investigation of lake sediments, including geochemical and palynological analyses, to reconstruct past changes in temperature and agricultural practices of pre-Viking and Viking societies in Southeastern Norway during the period between 200 and 1300 CE. The periods 200–300 and 800–1300 CE were warmer than the 300–800 CE period, which is known as the “Dark Ages Cold Period”. This cold period was punctuated by century-scale more temperate intervals, which were dominated by the cultivation of cereals and hemp (before 280 CE, 420–480 CE, 580–700 CE, and after 800 CE). In between, cold intervals were dominated by livestock farming. Our results demonstrate that the pre-Viking societies changed their agricultural strategy in response to climate variability during the Late Antiquity.

• Gaynor, Sean P.; Svensen, Henrik Hovland; Polteau, Stephane & Schaltegger, Urs (2022). Local melt contamination and global climate impact: Dating the emplacement of Karoo LIP sills into organic-rich shale. Earth and Planetary Science Letters. ISSN 0012-821X. 579. doi: 10.1016/j.epsl.2022.117371. Full text in Research Archive Show summary

  The emplacement of Large Igneous Provinces (LIPs) is commonly correlated with global climate change, and environmental and biological crises. To establish this complex causative link, chemical proxies from marine sedimentary sections must be temporally tied to LIP activity through high-precision geochronology. The temporal link is often ambiguous, especially as periods of environmental change are commonly shorter than the full duration of magmatic and volcanic activity in a LIP. Most importantly, temporal relations need to be established through precise and accurate U-Pb geochronology; however, mafic rocks are often undersaturated in zircon or baddeleyite. New U-Pb age determinations of pegmatitic pods from Karoo LIP dolerite sills into the Ecca Group of the Karoo Basin yield single crystal dates with uncertainties below 50 ka, which allow for a new, detailed assessment of this intrusive event. These samples yield complicated age spectra and Hf geochemistry, which indicate that localized assimilation of sedimentary rocks enabled zircon saturation within these mafic melts. Zircon crystallization age interpretations from these data indicate that sill emplacement within the Ecca Group was coeval across the basin within uncertainty of U-Pb dating, and therefore represents a period of particularly high magma flux. Since the Ecca Group is locally exceptionally rich in organic matter, the widespread and rapid sill-related contact metamorphism generated a significant volume of thermogenic volatiles. Given the temporal overlap of the emplacement of sills between 183.147 ± 0.059 Ma and 183.187 ± 0.133 Ma and the timing of the global Toarcian Oceanic Anoxic Event (TOAE), our data support a causal link between this discrete period of high flux emplacement of Karoo sills into the Ecca Group and the global climate change that took place during the Early Jurassic.

• Longman, Jack; Gernon, Thomas M.; Palmer, Martin R.; Jones, Morgan Thomas; Stokke, Ella Wulfsberg & Svensen, Henrik Hovland (2021). Marine diagenesis of tephra aided the Palaeocene-Eocene Thermal Maximum termination. Earth and Planetary Science Letters. ISSN 0012-821X. 571. doi: 10.1016/j.epsl.2021.117101.
• Percival, L.M.E.; Tedeschi, L.R.; Creaser, R.A.; Bottini, C.; Erba, E. & Giraud, F. [Show all 14 contributors for this article] (2021). Determining the style and provenance of magmatic activity during the Early Aptian Oceanic Anoxic Event (OAE 1a). Global and Planetary Change. ISSN 0921-8181. 200. doi: 10.1016/j.gloplacha.2021.103461.
• Sibik, Svetlana; Edmonds, Marie; Villemant, Benoit; Svensen, Henrik Hovland; Polozov, Alexander G. & Planke, Sverre (2021). Halogen Enrichment of Siberian Traps Magmas During Interaction With Evaporites. Frontiers in Earth Science. ISSN 2296-6463. 9. doi: 10.3389/feart.2021.741447. Full text in Research Archive
• Torsvik, Trond Helge; Svensen, Henrik; Steinberger, Bernhard; Royer, Dana L.; Jerram, Dougal Alexander & Jones, Morgan Thomas [Show all 7 contributors for this article] (2021). Connecting the Deep Earth and the Atmosphere. Geophysical Monograph Series. ISSN 0065-8448. 263, p. 413–453. doi: 10.1002/9781119528609.ch16.
• Heimdal, Thea Hatlen; Goddéris, Yves; Jones, Morgan Thomas & Svensen, Henrik Hovland (2021). Assessing the importance of thermogenic degassing from the Karoo Large Igneous Province (LIP) in driving Toarcian carbon cycle perturbations. Nature Communications. ISSN 2041-1723. 12. doi: 10.1038/s41467-021-26467-6. Full text in Research Archive
• Callegaro, Sara; Svensen, Henrik Hovland; Neumann, Else Ragnhild; Polozov, Alexander G.; Jerram, Dougal Alexander & Deegan, Frances M. [Show all 10 contributors for this article] (2021). Geochemistry of deep Tunguska Basin sills, Siberian Traps: correlations and potential implications for the end-Permian environmental crisis. Contributions to Mineralogy and Petrology. ISSN 0010-7999. 176. doi: 10.1007/s00410-021-01807-3. Full text in Research Archive
• Bastos, Lucas Pinto Heckert; Rodrigues, René; Pereira, Egberto; Bergamaschi, Sergio; Alferes, Carmen Lucia Ferreira & Augland, Lars Eivind [Show all 9 contributors for this article] (2021). The birth and demise of the vast epicontinental Permian Irati-Whitehill sea: Evidence from organic geochemistry, geochronology, and paleogeography. Palaeogeography, Palaeoclimatology, Palaeoecology. ISSN 0031-0182. 562. doi: 10.1016/j.palaeo.2020.110103.
• Stokke, Ella W.; Jones, Morgan Thomas; Riber, Lars; Haflidason, Haflidi; Midtkandal, Ivar & Schultz, Bo [Show all 7 contributors for this article] (2021). Rapid and sustained environmental responses to global warming: The Paleocene-Eocene Thermal Maximum in the eastern North Sea. Climate of the Past. ISSN 1814-9324. 17(5), p. 1989–2013. doi: 10.5194/cp-17-1989-2021. Full text in Research Archive
• Neumann, Else Ragnhild; Marsh, J.S.; Galerne, Christophe Yann; Polteau, Stephane; Svensen, Henrik & Planke, Sverre (2020). Co-existing low-Ti and high-Ti dolerites in two large dykes in the Gap Dyke swarm, southeastern Karoo Basin (South Africa). South African Journal of Geology. ISSN 1012-0750. 123(1), p. 19–34. doi: 10.25131/sajg.123.0003.
• Svensen, Henrik; Hammer, Øyvind; Chevallier, Luc; Jerram, Dougal Alexander; Silkoset, Petter & Polteau, Stephane [Show all 7 contributors for this article] (2020). Understanding thermogenic degassing in large igneous provinces: Inferences from the geological and statistical characteristics of breccia pipes in the western parts of the Karoo Basin. In Adatte, Thierry; Bond, David P.G. & Keller, Gerta (Ed.), Mass extinctions, volcanism, and impacts. The Geological Society of America. ISSN 9780813725444. p. 67–84.
• Heimdal, Thea Hatlen; Jones, Morgan Thomas & Svensen, Henrik (2020). Thermogenic carbon release from the Central Atlantic magmatic province caused major end-Triassic carbon cycle perturbations. Proceedings of the National Academy of Sciences of the United States of America. ISSN 0027-8424. 117(22), p. 11968–11974. doi: 10.1073/pnas.2000095117. Full text in Research Archive
• Schobben, Martin; Foster, William J.; Sleveland, Arve; Zuchuat, Valentin; Svensen, Henrik & Planke, Sverre [Show all 11 contributors for this article] (2020). A nutrient control on marine anoxia during the end-Permian mass extinction. Nature Geoscience. ISSN 1752-0894. 13, p. 640–646. doi: 10.1038/s41561-020-0622-1. Show summary

  Oxygen deprivation and hydrogen sulfide toxicity are considered potent kill mechanisms during the mass extinction just before the Permian–Triassic boundary (~251.9 million years ago). However, the mechanism that drove vast stretches of the ocean to an anoxic state is unclear. Here, we present palaeoredox and phosphorus speciation data for a marine bathymetric transect from Svalbard. This shows that, before the extinction, enhanced weathering driven by Siberian Traps volcanism increased the influx of phosphorus, thus enhancing marine primary productivity and oxygen depletion in proximal shelf settings. However, this non-sulfidic state efficiently sequestered phosphorus in the sediment in association with iron minerals, thus restricting the intensity and spatial extent of oxygen-depleted waters. The collapse of vegetation on land immediately before the marine extinction changed the relative weathering influx of iron and sulfate. The resulting transition to euxinic (sulfidic) conditions led to enhanced remobilization of bioavailable phosphorus, initiating a feedback that caused the spread of anoxic waters across large portions of the shelf. This reconciles a lag of >0.3 million years between the onset of enhanced weathering and the development of widespread, but geographically variable, ocean anoxia, with major implications for extinction selectivity.

• Zuchuat, Valentin; Sleveland, Arve; Twitchett, Richard; Svensen, Henrik; Turner, Holly & Augland, Lars Eivind [Show all 12 contributors for this article] (2020). A new high-resolution stratigraphic and palaeoenvironmental record spanning the End-Permian Mass Extinction and its aftermath in central Spitsbergen, Svalbard. Palaeogeography, Palaeoclimatology, Palaeoecology. ISSN 0031-0182. 554. doi: 10.1016/j.palaeo.2020.109732. Full text in Research Archive Show summary

  Research on the Permian-Triassic boundary (PTB) along the northern margins of Pangaea (exposed today in the Arctic region) has been heavily reliant on field observations, where data resolution was consequently determined by outcrop condition and accessibility. Core drilling in central Spitsbergen allowed for a near-complete recovery of two ~90 m cores through the PTB. Analyses of the core and nearby outcrops include stratigraphic logging and sampling, XRF scanning, petrography, biostratigraphy, isotope geochemistry, and geochronology. The First Appearance Datum (FAD) of H. parvus in Svalbard places the base of the Triassic ca. 4 m above the base of the Vikinghøgda Formation, and ca. 2.50 m above the End-Permian Mass Extinction (EPME) and its associated sharp negative δ13C. The PTB therefore falls within the Reduviasporonites chalastus Assemblage Zone in Svalbard. Precise U-Pb TIMS dating of two zircon crystals in a tephra layer just above the first documented Hindeodus parvus in Svalbard gives an age of 252.13 ± 0.62 Ma. High-resolution palaeoenvironmental proxies, including Si/kcps (kilo counts per second), Zr/Rb, K/Ti, Fe/K, and V/Cr, indicate a transition towards a more arid climate in the earliest Triassic, contemporaneous with prolonged bottom-water dysoxic/anoxic conditions, following an increase in volcanic activity in the Late Permian. Statistical analysis of Zr/Rb, K/Ti and V/Cr elemental ratios suggests that the system was impacted by long-eccentricity (400 kyr) cyclicity. The δ13C excursion in organic carbon (δ13Corg) record signals a large negative carbon isotope excursion (CIE) associated with the mass extinction event, but also records a second, smaller negative CIE ca. 22 m above this interval. This younger δ13Corg excursion correlates to similar CIEs in the Dienerian (late Induan) records of other sections, notably in the Tethys Ocean, which have been interpreted as recording a small biotic crisis during the post-extinction recovery. Evidence of this negative CIE in Spitsbergen suggests that the Dienerian crisis may have been global in extent. The negative δ13Corg values are associated with evidence for dysoxia or anoxia in the core, and the occurrence of tephra layers in the same interval suggests a possible connection between the Dienerian crisis and a discrete episode of volcanic activity.

• Polteau, Stephane; Planke, Sverre; Zastrozhnov, Dmitrii; Abdelmalak, Mohamed Mansour; Lebedeva-Ivanova, Nina & Eckhoff Planke, Ellen [Show all 14 contributors for this article] (2020). Upper cretaceous-paleogene stratigraphy and development of the Mímir High, Vøring transform margin, Norwegian Sea. Marine and Petroleum Geology. ISSN 0264-8172. 122. doi: 10.1016/j.marpetgeo.2020.104717. Full text in Research Archive Show summary

  Transform margins represent strike-slip type of plate boundaries that form during continental breakup and initial ocean opening. They are often characterized by margin-parallel highs with exposed pre- and syn-rift sequences. The Vøring Transform Margin, offshore mid-Norway, initiated in the earliest Eocene during the opening of the NE Atlantic. Here, 2D seismic reflection data reveal a transform margin high, the Mímir High. The western flank of this undrilled structure is a kilometer-high escarpment where seismic reflections of pre-breakup age are truncated at the seafloor. The aim of this study was to recover seabed rock samples from the outcropping or shallowly buried sedimentary sequences to provide a geological tie to the regional seismic framework, thereby constraining the basin history and tectono-stratigraphic development. Seabed samples were successfully collected from 14 gravity core and Selcore stations and 10 ROV (remotely operated vehicle) sites along a 750 m high sampling profile, recovering clay, shales, sandstones and glacial dropstones. Biostratigraphy results revealed that the ages of the sedimentary rocks follow the stratigraphic order predicted by the initial seismic interpretation, with Upper Cretaceous sediments at the base and lower Eocene sediments at the top. The integrated interpretation shows that the Mímir High area, including parts of the outer Vøring and Møre basins and the proto-Jan Mayen Microplate Complex, were characterized by the deposition of late Campanian to early Maastrichtian, near coastal and shale-dominated sequences with poor source rock qualities. The early Paleocene samples indicate deep marine conditions that abruptly ended by rapid uplift of the Mímir High in the earliest Eocene. Finally, a reworked Pliensbachian palynomorph assemblage in potential early Eocene strata indicate the presence of exposed Mesozoic sequences in the vicinity of the Mímir High. We argue that some of the lower Eocene sediments where deposited within a hypothetical drainage system sourced from Greenland (Traill Ø or Jameson Land) and/or from the Jan Mayen Ridge prior to continental separation, and not the result of recent ice-rafting.

• Stokke, Ella Wulfsberg; Jones, Morgan Thomas; Tierney, Jessica; Svensen, Henrik & Whiteside, Jessica H. (2020). Temperature changes across the Paleocene-Eocene Thermal Maximum – a new high-resolution TEX86 temperature record from the Eastern North Sea Basin. Earth and Planetary Science Letters. ISSN 0012-821X. 544. doi: 10.1016/j.epsl.2020.116388. Full text in Research Archive
• Augland, Lars Eivind; Ryabov, Viktor V.; Vernikovsky, Valery A.; Planke, Sverre; Polozov, Alexander & Callegaro, Sara [Show all 8 contributors for this article] (2019). The main pulse of the Siberian Traps expanded in size and composition. Scientific Reports. ISSN 2045-2322. 9. doi: 10.1038/s41598-019-54023-2. Full text in Research Archive Show summary

  Emplacement of large volumes of (sub)volcanic rocks during the main pulse of the Siberian Traps occurred within <1 m.y., coinciding with the end-Permian mass extinction. Volcanics from outside the main Siberian Traps, e.g. Taimyr and West Siberia, have since long been correlated, but existing geochronological data cannot resolve at a precision better than ~5 m.y. whether (sub)volcanic activity in these areas actually occurred during the main pulse or later. We report the first high precision U-Pb zircon geochronology from two alkaline ultramafic-felsic layered intrusive complexes from Taimyr, showing synchronicity between these and the main Siberian Traps (sub)volcanic pulse, and the presence of a second Dinerian-Smithian pulse. This is the first documentation of felsic intrusive magmatism occurring during the main pulse, testifying to the Siberian Trap’s compositional diversity. Furthermore, the intrusions cut basal basalts of the Taimyr lava stratigraphy hence providing a minimum age of these basalts of 251.64 ± 0.11 Ma. Synchronicity of (sub)volcanic activity between Taimyr and the Siberian Traps imply that the total area of the Siberian Traps main pulse should include a ~300 000 km2 area north of Norilsk. The vast aerial extent of the (sub)volcanic activity during the Siberian Traps main pulse may explain the severe environmental consequences.

View all works in Cristin

• Konglevold, Laila; Christiansen, Stefan; Svensen, Henrik Hovland & Bjørshol, Anja (2023). Verdens navle. House of Foundation. ISBN 9788284170534. 255 p.
• Svensen, Henrik Hovland (2022). Et land av stein. Bergartene som har formet Norge. Kagge Forlag AS. ISBN 9788248929901. 311 p.
• Svensen, Henrik; Græsli, Hans; Aga Schioldborg, Alexandra & Schanz, Kristin (2020). Kompass. Gyldendal Undervisning. ISBN 9788205524521. 271 p.
• Svensen, Henrik (2020). Under asfalten. Oslos naturhistorie gjennom to milliarder år. Kagge Forlag AS. ISBN 9788248926399. 251 p.

View all works in Cristin

• Svensen, Henrik Hovland (2024). Grafikk i Østfold, deltakelse i gruppeutstilling.
• Svensen, Henrik Hovland (2024). Light in darkness - linocut workshop.
• Svensen, Henrik Hovland (2024). Vulkanutbrudd på Island og hvordan de kan påvirke oss.
• Svensen, Henrik Hovland (2024). Geologen som ble besatt av kunst. [Business/trade/industry journal]. Apollon.
• Svensen, Henrik Hovland (2024). Oppdatering om vulkanutbruddet på Island (januar 2024). [TV]. NRK Dagsrevyen.
• Svensen, Henrik Hovland (2024). Vulkanutbruddet på Island (januar 2024). [Radio]. NRK Nyhetsmorgen (radio/TV).
• Bond, David; Callegaro, Sara; Davies, Joshua; Deegan, Frances; Galloway, Jennifer & Gaynor, Sean [Show all 14 contributors for this article] (2023). Meet the Authors. Elements. ISSN 1811-5209. 19(5), p. 265–266. doi: 10.2138/gselements.19.5.265.
• Svensen, Henrik Hovland (2023). Kunst rett vest 2023.
• Svensen, Henrik Hovland (2023). Om vulkanutbruddet på Island (desember 2023). [Radio]. NRK Nyhetsmorgen (radio/TV).
• Svensen, Henrik Hovland (2023). Oslos geologiske historie.
• Whattam, Jack; Svensen, Henrik Hovland; Midtkandal, Ivar; Callegaro, Sara & Jerram, Dougal Alexander (2023). Intermittent cessation and renewal of volcanism in the Oslo Rift revealed through detailed mapping and stratigraphy.
• Svensen, Henrik Hovland (2023). Du kan ofte se granitt og gneis når du går tur, men hvordan ble de til? . [Internet]. forskning.no.
• Callegaro, Sara; Svensen, Henrik Hovland; Deegan, Frances M.; Planke, Sverre & Polozov, Alexander (2022). Magma-host rock interaction in basaltic sills from the Siberian Traps (Tunguska basin, Russia): mineral scale and whole-rock perspectives.
• Callegaro, Sara; Svensen, Henrik Hovland; Heimdal, Thea Hatlen; Kjøll, Hans Jørgen; Harstad, Andreas Olaus & Neumann, Else Ragnhild (2022). New insights on shallow intrusions from the early stage of the Oslo Rift. .
• Svensen, Henrik Hovland (2022). Hva skjuler seg under asfalten i Oslo?
• Svensen, Henrik Hovland (2022). Redd for antropocen.
• Svensen, Henrik Hovland (2022). Østfolds vakre bergarter og mystiske fortid.
• Svensen, Henrik Hovland & Kongevold, Laila (2022). Bokbad på utstillingen "En verden under føttene".
• Svensen, Henrik Hovland (2022). En verden under føttene.
• Svensen, Henrik Hovland & Torgersen, Eivind (2022). Norske byggeklosser – bergartene som bygget landet.
• Svensen, Henrik Hovland & Müller, Reidar (2022). Lanseringssamtale, Et land av stein.
• Svensen, Henrik Hovland (2022). Geologisk vandring i Oslo sentrum.
• Zuchuat, Valentin; Augland, Lars Eivind; Jones, Morgan Thomas; Sleveland, Arve R.N.; Twitchett, Richard & Tovar, Francisco J Rodríguez [Show all 13 contributors for this article] (2022). The Permian-Triassic boundary across the Barents Shelf: an intricate record of climate change, mass extinction, recovery, and basin reorganisation. EGU General Assembly. doi: 10.5194/egusphere-egu22-2379.
• Einevoll, Gaute & Svensen, Henrik Hovland (2022). Podcast #51 i Vett og vitenskap. [Internet]. Podcast "Vett og vitenskap".
• Svensen, Henrik Hovland (2022). Oslo under asfalten.
• Svensen, Henrik Hovland (2022). Ny bok om bergarter i Norge. [Radio]. NRK P1+ Holm.
• Svensen, Henrik Hovland; Bøckmann, Petter & Bjorå, Charlotte Sletten (2022). Abels tårn. [Radio]. EKKO; NRK P2.
• Berndt, Christian; Planke, Sverre; Zarikian, Carlos A.; Bünz, Stefan; Karstens, Jens & Svensen, Henrik Hovland [Show all 8 contributors for this article] (2022). Shallow-water hydrothermal venting in the North Atlantic during the Paleocene Eocene Thermal Maximum. Show summary

  The Paleocene Eocene Thermal Maximum (PETM, ~56 Ma) was a rapid global warming of 5-6 ºC resulting from massive (>2000 Gigatons) carbon emissions. A potential release mechanism is thermogenic gas from contact metamorphism of carbon-bearing sediments due to magma intrusions into sedimentary basins. Here, we present seismic data and borehole information from the North Atlantic Igneous Province. They show that even in the center of the rift system, water depths were sufficiently shallow to allow most gas released from hydrothermal vent systems to bypass the water column. The shape of the vent craters and stratified infill suggest vigorous explosive gas release during the initial phase of vent formation and rapid shallow marine and largely undisturbed infill thereafter. The recorded negative carbon isotope excursion and occurrence of the index taxon Apectodinium augustum in the crater-infill support assignment to a latest Paleocene to earliest Eocene vent formation. The data support a scenario where magmatic sill emplacement and resulting hydrothermal activity rapidly injected thermogenic greenhouse gas into the atmosphere

• Bjærke, Marit Ruge; Ekström, Anders; Hastrup, Frida & Svensen, Henrik Hovland (2022). Bridging an epistemological gap: Roundtable on the importance of cooperation between the humanities and the natural sciences. .
• Svensen, Henrik Hovland (2022). Da Oslo eksploderte.
• Svensen, Henrik Hovland (2022). Oslos naturhistorie gjennom to milliarder år - og vulkanene på Ullern.
• Svensen, Henrik Hovland (2022). The Huken quarry and the resulting landscapes.
• Svensen, Henrik Hovland (2022). Science and art: Experience from collaboration with artists - and using art in outreach .
• Svensen, Henrik Hovland (2022). Geologien i Oslo-området.
• Svensen, Henrik Hovland (2022). Under asfalten.
• Svensen, Henrik Hovland (2021). Abels Tårn. [Radio]. NRK P2.
• Svensen, Henrik Hovland (2021). Abels Tårn. [Radio]. NRK P2.
• Svensen, Henrik Hovland (2021). Under asfalten. Oslos naturhistorie.
• Svensen, Henrik Hovland (2021). Under asfalten.
• Svensen, Henrik Hovland (2021). Geologien i Oslo området.
• Svensen, Henrik Hovland (2021). En by skapt av lava og is - Oslos naturhistorie gjennom to milliarder år.
• Svensen, Henrik Hovland (2021). Lærdommer fra fortidens masseutryddelser og klimaendringer.
• Svensen, Henrik Hovland (2021). Tanker om faget.
• Svensen, Henrik Hovland (2021). Om Kolsås og rombeporfyr.
• Svensen, Henrik Hovland (2021). Geological highlihts in Oslo - Excursion.
• Svensen, Henrik Hovland (2021). Oslos geologiske historie med fokus på leire.
• Svensen, Henrik Hovland (2021). Et vindu til den dype tiden: Erfaringer fra et geologisk-kunstnerisk samarbeid.
• Svensen, Henrik Hovland (2021). Under asfalten- Oslos naturhistorie gjennom to milliarder år.
• Svensen, Henrik Hovland (2021). Vulkaner og jordens revolusjoner.
• Callegaro, Sara; Svensen, Henrik Hovland; Jerram, Dougal Alexander; Neumann, Else Ragnhild; Deegan, Frances M. & Polozov, Alexander [Show all 7 contributors for this article] (2021). Geochemistry of low-Ti Siberian Traps sills from the Tunguska Basin bears evidence of magma-crust interaction.
• Zuchuat, Valentin; Augland, Lars Eivind; Jones, Morgan Thomas; Twitchett, Richard; Rodríguez-Tovar, Francisco J. & Hammer, Øyvind [Show all 11 contributors for this article] (2021). Facies changes, volcanism, and mass extinction conundrum: the Permian-Triassic boundary across the Barents Sea Shelf. Show summary

  The most dramatic mass extinction the Earth has ever experienced occurred 252 million years ago, at the end of the Permian. It was likely triggered by the volcanic eruptions and magmatic intrusions associated with the Siberian Traps Large Igneous Province (LIP), leading to dramatic climatic changes, with consequences lasting well into the Early Triassic. Here, we present a summary of the findings from the study of several sedimentary successions distributed across the Barents Sea that spanned the End Permian Mass Extinction (EPME) and the Permian-Triassic boundary. The four studied successions included the renowned Festningen section in the outer part of Isfjorden, western Spitsbergen; the DD-1 core and the associated river section in Deltadalen, central Spitsbergen; a core drilled offshore Kvitøya in northern Svalbard, and a core drilled on the Horda Platform in the Barents Sea. Datasets of various research lines were collected from these sections including sedimentology, organic geochemistry, isotope, geochronology, XRF, mineralogy, ichnology, palaeontology, palynology and digital outcrop data. Historically, the Permian-Triassic boundary exposed today in Svalbard (and at various places across the High Arctic regions) was placed at the very prominent and abrupt facies change occurring between the siliceous mudstones or spiculites of the Kapp Starostin Formation, and the overlying soft, non-siliceous mudstones and siltstones of the Vardebukta and Vikinghøgda formations. The abruptness of this facies change, which also marks the demise of sponges, led to the belief that it represented a hiatus or a gap of several million years, with the uppermost Permian strata missing from the sedimentary record, while the mudstones of the Vardebukta and Vikinghøgda formations were definitely of Lower Triassic age, based on ammonoid biostratigraphy. Hindeodus parvus, the conodont that defines the base of the Triassic, was for the first time identified in Svalbard a few meters above the lithostratigraphic boundary, which is therefore of Upper Permian age. Additionally, our new data show that sedimentation was continuous across this lithostratigraphic boundary. This transition from the Kapp Starostin Formation to the Vardebukta and Vikinghøgda formations was accompanied by a major reorganisation/inversion of the basin(s), but its exact nature remains puzzling. Further, all measured sections record the EPME, which is associated with a 6-8 ‰ δ13CVPDB negative excursion, and measured between the lithostratigraphic and the Permian-Triassic boundaries. These negative isotopic excursions are found in close vicinity to several tephra layers that have been precisely dated at 252.13 ± 0.62 Ma, strongly suggesting a connection to the Siberian Traps LIP event. The mass extinction is also confirmed by the very rapid decreasing of trace fossil abundance and diversity, as anoxia spread across the water from proximal and shallow water to deeper settings. Geochemical and ichnological data indicate the occurrence of several anoxic pulses, intersected by very brief episodes of improved oxygenation levels. It took ca. 145 Kyr for life to recover after the extinction event, based on sedimentation rate calculations. Data also suggest that a shift towards more arid climatic conditions and increased eutrophication on land accompanied the EPME.

• Planke, Sverre; Polozov, Alexander; Millett, John M; Jerram, Dougal Alexander; Zastrozhnov, Dmitrii & Svensen, Henrik (2020). Emergent and invasive magmatism of the Siberian Traps in a wet forest environment. NGF abstracts and proceedings.
• Svensen, Henrik & Müller, Reidar (2020). Under asfalten – Oslo lag for lag. Henrik Svensen i samtale Reidar Müller.
• Svensen, Henrik (2020). Bli med under asfalten i Oslo.
• Svensen, Henrik (2020). Oslos geologiske historie - en serie i tre deler i Ekko, NRK P2. [Radio]. NRK P2 Ekko.
• Heimdal, Thea Hatlen; Jones, Morgan Thomas; Svensen, Henrik & Callegaro, Sara (2020). The Central Atlantic Magmatic Province (CAMP) and the end-Triassic crisis.
• Jones, Morgan Thomas; Stokke, Ella Wulfsberg; Augland, Lars Eivind; Svensen, Henrik; Pogge von Strandmann, Philip A.E. & Rooney, Alan (2020). Constraining the activity of the North Atlantic Igneous Province across the Paleocene-Eocene boundary.
• Jones, Morgan Thomas; Stokke, Ella Wulfsberg; Augland, Lars Eivind; Pogge von Strandmann, Philip A.E.; Liu, Emma J. & Mather, Tamsin [Show all 13 contributors for this article] (2020). Constraining North Atlantic Igneous Province (NAIP) activity during the late Paleocene and early Eocene.
• Torsvik, Trond Helge; Svensen, Henrik; Steinberger, Bernhard; Royer, Dana L.; Jerram, Dougal Alexander & Jones, Morgan Thomas [Show all 7 contributors for this article] (2020). Connecting the Deep Earth and the Atmosphere.
• Svensen, Henrik (2020). Guide til Oslos geologiske skatter. [Internet]. Titan, UiO.
• Svensen, Henrik (2020). Dro på jakt etter vulkaner. [Newspaper]. Aftenposten Junior.
• Svensen, Henrik (2020). Oslos lange geologiske historie. [Radio]. NRK P2 Studio 2.
• Svensen, Henrik (2020). Ny bok om Oslos geologiske historie. [Radio]. NRK Østlandssendingen.
• Svensen, Henrik (2020). Lansering av Under asfalten, bokbad.
• Svensen, Henrik (2020). Om Oslos geologiske historie.
• Svensen, Henrik (2020). Denne steinen på Ekebergsletta er viktigere enn du tror. [Newspaper]. Aftenposten.
• Svensen, Henrik (2020). Oppdagelsen av Jotunfjeldene – når geologi blir kunst. [Internet]. plnty.
• Stokke, Ella Wulfsberg; Jones, Morgan Thomas; Tierney, Jessica E.; Riber, Lars; Svensen, Henrik & Whiteside, Jessica H. (2020). Volcanic cooling followed by a warm and wet Paleocene-Eocene Thermal Maximum in Denmark.
• Bajard, Manon Julietto Andree; Ballo, Eirik Magnus Gottschalk; Støren, Eivind Wilhelm Nagel; Bakke, Jostein; Høeg, Helge Irgens & Loftsgarden, Kjetil [Show all 9 contributors for this article] (2020). Tracing socio-environmental dynamics and climate changes in the period 300-1300 CE in Scandinavia from lake sediments. Show summary

  Understanding large volcanic eruptions impacts on environments and societies is necessary to consider future climate and socio-environmental interactions. Lake sediments can record these dynamics on a continuous long time scale and include at the same time footprints from volcanic eruptions, climate changes and human activities. We analysed the sediments of Lake Ljøgottjern, located southeastern Norway. The largest burial mound of Northern Europe was built in the mid-6th century on the shore of this lake and makes this place an ideal site to study human-environmental interactions throughout the last millennia. Using a multi-proxy analysis of this sedimentary record, including 14C dating, geochemistry, as well as palynological data, we reconstructed temperature and socio-environmental changes in this area between 300 and 1300 CE (Common Era). We associated changes in Ca/Ti ratio with changes in temperature. The period between 300 and 800 CE was colder than the periods 200-300 and 800-1300 CE. Five abrupt cooling events seem to be linked to weakened positive NAO (North Atlantic Oscillation) phases, and two of them can also be linked to the two largest volcanic events of the period (i.e. the 536/540 CE double event, and 1257 CE eruption of Samalas). Palynological data indicate a decrease of the human activities and reforestation of the area in the 6th century. This abandonment is consistent with archaeological findings and could be related to the 536/540 cooling event. Very little activities are then recorded between 700 and 850 CE. Agricultural activities start again strongly in the Viking age with increase in temperature.

• Åmli, Hanne; Fossen, Haakon & Svensen, Henrik (2020). Meta Morhp.
• Svensen, Henrik (2019). Menneskets fotavtrykk. Morgenbladet. ISSN 0805-3847.

View all works in Cristin