ORCID Profile
0000-0001-9147-8592
Current Organisations
University of Tasmania
,
McPhie Volcanology
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Publisher: The National and University Library of Iceland
Date: 06-2020
Abstract: Surtsey was drilled in 2017 in the context of the Surtsey Underwater volcanic System for Thermophiles, Alteration processes and INnovative Concretes (SUSTAIN) project. Vertical drill holes, SE-02a and SE02b (drilled to 191.64 m), and angled drill SE-03 (drilled to 354.05 m), intersected armoured lapilli tuff and lapilli tuff generated mainly by explosive eruptions at Surtur from November 1963 to January 1964. The top ~20 m of lapilli tuff was erupted from Surtungur. Intervals of coherent basalt in SE-02b (15.7 to 17 m and cm at the end) and in SE-03 ( m at ~60 m and ~238 m, and 10 m near the base) are probably intrusions that may have fed the small lavas erupted at Surtur ~2.5 years later. Although collared only a few m from the 1979 drill hole, neither SE-02a nor SE-02b intersected the 13-m-thick interval of basalt found in the 1979 drill hole. The 2017 drill cores are entirely lithified and variably altered, reflecting the effects of hydrothermal alteration and cement deposition on the originally fresh, unconsolidated ash and lapilli. Drill hole SE-03 was drilled on an azimuth of 264o and at 55o from horizontal, obliquely crossing the crater- and conduit-fill of Surtur. Although the exact trajectory of SE-03 is unknown (the drill hole was not surveyed), the drill hole ended at a vertical depth of ~100 m below the pre-eruption sea floor, however, sedimentary facies known to underlie the sea floor nearby were not intersected. Surtur eruptions therefore excavated the pre-eruption sea floor to a depth of several tens of m.
Publisher: American Geophysical Union (AGU)
Date: 12-2021
DOI: 10.1029/2021GC010011
Abstract: We use the tephrostratigraphic framework along the Aegean Volcanic Arc established in Part 1 of this contribution to determine hemipelagic sedimentation rates, calculate new tephra ages, and constrain the minimum magnitudes of (sub)plinian eruptions of the last 200 kyrs. Hemipelagic sedimentation rates range from ∼0.5 cm/kyr up to ∼40 cm/kyr and vary laterally as well as over time. Interpolation between dated tephras yields an eruption age of ∼37 ka for the Firiplaka tephra, showing that explosive volcanism on Milos is ∼24 kyrs younger than previously thought. The four marine Nisyros tephras (N1 to N4) identified in Part 1 (including the Upper (N1) and Lower (N4) Pumice) have ages of ∼57 ka, ∼63 ka, ∼69 ka, and ∼76 ka, respectively. Eruption ages for the Yali‐1 and Yali‐2 tephras are ∼55 ka and ∼34 ka, respectively. The Yali‐2 tephra comprises two geochemically and laterally distinct marine facies. The southern facies is identical to the Yali‐2 fall deposit on land but the western facies has slightly less evolved glass compositions. Overall, erupted plinian and co‐ignimbrite fall tephra volumes range from to 56 km 3 (excluding possible caldera fillings and ignimbrite volumes), and 80% of the eruptions had magnitude 5.5 M ≤ 7.2 ( M = log(m)‐7 m = erupted magma mass in kg). Twenty percent of the tephras represent 3.2 M 5.5 eruptions. The long‐term average tephra magma mass flux through highly explosive eruptions of Santorini is estimated at ∼40 kg/s. The analogous data for the Kos‐Yali‐Nisyros volcanic complex is less‐well constrained but similar to Santorini.
Publisher: Frontiers Media SA
Date: 17-10-2018
Publisher: American Geophysical Union (AGU)
Date: 12-2021
DOI: 10.1029/2021GC010010
Abstract: The Milos, Christiana‐Santorini‐Kolumbo (CSK) and Kos‐Yali‐Nisyros (KYN) volcanic complexes of the Aegean Volcanic Arc have repeatedly produced highly explosive eruptions from at least ∼360 ka into historic times and still show recent unrest. We present the marine tephra record from an array of 50, up to 7.4 m long, sediment cores along the arc collected in 2017 during RV Poseidon cruise POS513, which complements earlier work on distal to ultra‐distal eastern Mediterranean sediment cores. A unique set of glass‐shard trace element (LA‐ICPMS) compositions complements our major element (EMP) data on 220 primary ash layers and 40 terrestrial s les to support geochemical fingerprinting for correlations with 19 known tephras from all three volcanic complexes and with the 39 ka C anian Ignimbrite from the C i Flegrei, Italy. The correlations include 11 eruptions from CSK (Kameni, Kolumbo 1650, Minoan, Cape Riva, Cape Tripiti, Upper Scoriae 1 and 2, Middle Pumice, Cape Thera, Lower Pumice, Cape Therma 3). We identify a previously unknown widespread tephra from a plinian eruption on Milos (Firiplaka Tephra). Near the KYN we correlate marine tephras with the Kos Plateau Tuff, the Yali 1 and Yali 2 tephras, and the Upper and Lower Pumice on Nisyros. Between these two major tephras, we found two tephras from Nisyros not yet observed on land. The four Nisyros tephras form a systematic trend toward more evolved magma compositions. In the companion paper we use the tephrostratigraphic framework established here to constrain new eruption ages and magnitudes as a contribution to volcanic hazard assessment.
Publisher: Elsevier BV
Date: 2019
Publisher: Springer Science and Business Media LLC
Date: 11-12-2015
Publisher: Geological Society of America
Date: 11-2011
DOI: 10.1130/G32205.1
Publisher: Springer Science and Business Media LLC
Date: 05-1990
DOI: 10.1007/BF00302047
Publisher: Elsevier BV
Date: 09-2018
Publisher: Elsevier BV
Date: 04-2016
Publisher: Society of Economic Geologists
Date: 05-1992
Publisher: Elsevier BV
Date: 08-2007
Publisher: Springer Science and Business Media LLC
Date: 14-05-2020
Publisher: Elsevier BV
Date: 11-2020
Publisher: Geological Society of America
Date: 07-2009
DOI: 10.1130/G30007A.1
Publisher: Elsevier BV
Date: 08-2016
Publisher: Elsevier BV
Date: 05-2010
Publisher: Society of Economic Geologists
Date: 09-2017
Publisher: Geological Society of America
Date: 08-2011
DOI: 10.1130/G31952.1
Publisher: Elsevier BV
Date: 05-2017
Publisher: Elsevier BV
Date: 10-2017
Publisher: Springer Science and Business Media LLC
Date: 04-02-2022
DOI: 10.1007/S00445-022-01528-W
Abstract: The March–April 2007 Piton de la Fournaise basaltic eruption was the most significant eruption on La Réunion Island in historical times. On 2 April, a fissure opened on the southeastern flank of the volcano. Vigorous fountains fed lavas that rapidly reached the coast. Three days later, on the 5–6 April, major caldera collapse occurred at the summit, affecting the floor and walls of Dolomieu caldera. Monitoring records, primarily webcam images, have been analysed and integrated with geophysical data to reconstruct the chronology of events at the summit during caldera collapse. Those events included progressive subsidence of the former caldera floor, landslides, explosions, lava emissions and steam fumaroles, and lasted until 19 April though diminished greatly in frequency after 7 April. For two days after the main caldera collapse on 5 April, subsidence increments, intracaldera lava emission and explosions were closely associated in time and in location. Abundant steam and wet talus on the caldera walls imply that the shallow hydrothermal system and/or groundwater were exposed by subsidence. The presence of juvenile components in ash deposited at the summit during caldera collapse and the close link between intracaldera lavas and explosions suggest that many explosions were phreatomagmatic. Although caldera collapse was related to magma withdrawal from beneath the summit via the flank vent activity, numerous intracaldera lava emissions indicated that magma was nevertheless present at the summit during caldera collapse. We infer that the lava emissions were fed by an intrusion emplaced at the end of March into the eastern summit region and that the intrusion was being actively recharged during caldera collapse. Caldera collapse involved a complex combination of magma withdrawal and magma replenishment at separate summit reservoirs.
Publisher: Elsevier BV
Date: 12-2017
Publisher: American Geophysical Union (AGU)
Date: 02-03-2020
DOI: 10.1029/2019GL086768
Publisher: Informa UK Limited
Date: 20-05-2018
Publisher: Elsevier BV
Date: 05-2008
Publisher: Informa UK Limited
Date: 06-02-2020
Publisher: Springer Science and Business Media LLC
Date: 09-02-2006
Publisher: Springer Science and Business Media LLC
Date: 27-04-2021
Publisher: Elsevier BV
Date: 05-2002
Publisher: Informa UK Limited
Date: 16-03-2023
Publisher: Copernicus GmbH
Date: 12-06-2019
Abstract: Abstract. The 2017 Surtsey Underwater volcanic System for Thermophiles, Alteration processes and INnovative concretes (SUSTAIN) drilling project at Surtsey volcano, sponsored in part by the International Continental Scientific Drilling Program (ICDP), provides precise observations of the hydrothermal, geochemical, geomagnetic, and microbiological changes that have occurred in basaltic tephra and minor intrusions since explosive and effusive eruptions produced the oceanic island in 1963–1967. Two vertically cored boreholes, to 152 and 192 m below the surface, were drilled using filtered, UV-sterilized seawater circulating fluid to minimize microbial contamination. These cores parallel a 181 m core drilled in 1979. Introductory investigations indicate changes in material properties and whole-rock compositions over the past 38 years. A Surtsey subsurface observatory installed to 181 m in one vertical borehole holds incubation experiments that monitor in situ mineralogical and microbial alteration processes at 25–124 ∘C. A third cored borehole, inclined 55∘ in a 264∘ azimuthal direction to 354 m measured depth, provides further insights into eruption processes, including the presence of a diatreme that extends at least 100 m into the seafloor beneath the Surtur crater. The SUSTAIN project provides the first time-lapse drilling record into a very young oceanic basaltic volcano over a range of temperatures, 25–141 ∘C from 1979 to 2017, and subaerial and submarine hydrothermal fluid compositions. Rigorous procedures undertaken during the drilling operation protected the sensitive environment of the Surtsey Natural Preserve.
Publisher: Geological Society of America
Date: 25-01-2018
DOI: 10.1130/B31900.1
Publisher: Springer Science and Business Media LLC
Date: 04-05-2000
Publisher: Elsevier BV
Date: 11-2020
No related grants have been discovered for Jocelyn McPhie.