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West Antarctic Margin Signatures of Ice Sheet Evolution

Periodic Reporting for period 1 - WAMSISE (West Antarctic Margin Signatures of Ice Sheet Evolution)

Reporting period: 2018-10-31 to 2020-10-30

The evolution of the Antarctic ice sheets has been widely debated. According to several studies a continent-wide ice sheet first developed during the early Oligocene and subsequently it experienced many cycles of advance and retreat. Tectonic, oceanographic, climatic and ice dynamic processes have been pointed to as the primary factors controlling this oscillation. However, their relative influence is still controversial. Middle Miocene growth of the Antarctic ice sheet has been related to intensification of the Antarctic Circumpolar Current. It was followed by warm episodes during the Miocene Climate Optimum (∼17-14 Ma) and during the Pliocene when collapse of the West Antarctic Ice Sheet has been suggested. However, the stratigraphic signature of such a collapse has not been recognized on West Antarctic continental margins. The main aim of WAMSISE is examine the record of ice sheet evolution on West Antarctic continental margins from middle Miocene to present and clarify the factors controlling the major sedimentary changes and their global implications. To date, the research developed under WAMSISE has been focussed on the middle Miocene ice sheet oscillation over the Ross Sea continental shelf. The insights suggest ice sheet advance on the paleo continental shelf during short time intervals prior to the Miocene Climate Optimum, which was followed by widespread marine-based ice sheet advance on the Ross Sea during the Middle Miocene Climate Transition (∼14 Ma). Additional work developed in the Drake Passage and Scotia Sea reveals a link between the regional variability of the bottom-water flows and the Antarctic ice sheets dynamics from late Miocene to present.
The present reporting period includes the secondment at National Institute of Oceanography and Experimental Geophysics (OGS) in Italy, and the outgoing phase of the global MSCA at the Antarctic Research Centre – Victoria University of Wellington (VUW) in New Zealand. In addition, the researcher participated in the two months International Ocean Discovery Program (IODP) Expedition 382, considered as a short research stay.
During this period the project database [Work package (WP) 0] has been compiled. The IHS Kingdom project is completed and constitutes an essential tool for the development of WAMSISE. The project contains all the seismic profiles along the West Antarctic Margin and the logged physical properties of the sites recovered during IODP Expedition 374, DSDP Legs 28 and 35, and ODP Leg 178.
Seismic-stratigraphic analyses and core-log-seismic correlations in the Ross Sea continental shelf [WP1] have resulted in a scientific manuscript entitled ‘Early and middle Miocene ice sheet dynamics in the Ross Sea: results from integrated core-log-seismic interpretation’. It was submitted for publication to Geological Society of America Bulletin in June 2020. The results point to a regional transition from growth of isolated ice caps to widespread ice sheets occurred through Miocene in the Ross Sea. A second manuscript is currently in preparation, presenting the correlation of the latest insights along the middle and outer continental shelf with the sites recovered by the Antarctic Drilling Project (ANDRILL) in the southwesternmost Ross Sea.
The researcher participation in IODP Expedition 382 in the Drake Passage has resulted on a scientific paper entitled ‘Miocene to present oceanographic variability in the Scotia Sea and Antarctic ice sheets dynamics: Insight from revised seismic-stratigraphy following IODP Expedition 382’, recently accepted in Earth and Planetary Science Letters. This publication updates the age models of the major events in the Scotia Sea from late Miocene and relates them to regional variability of the oceanic circulation pattern associated with the oscillation of the Antarctic ice sheets. Sortable silt analyses on IODP Expedition 382 samples have been delayed due to COVID-19 lockdowns. Once implemented, the researcher expects to provide insights on the regional variability of the bottom flows between late Miocene and the present-day. The work derived from the IODP Expedition 382 will partly substitute WP2 and WP3 as agreed in the project amendment provided in November 2019.
In addition, the researcher has published three papers on high impact scientific journals as result of previous work and have collaborated on two additional papers as a co-author. She is also co-author the IODP Expedition 382 scientific reports and two related manuscripts.
The researcher has participated in five international conferences, three of them remotely due to COVID-19 restrictions. She has been convener in two sessions at the XIII International Symposium on Antarctic Earth Sciences (2019, South Korea) and West Antarctic Ice Sheet Workshop (2020, online). She has acted as moderator in APECS-SCAR workshop and SCAR Online (2020, online). She has been involved in twelve conference contributions and was lead author on two of them [lead author conference contributions: Perez, L.F. et al. Stratigraphic architecture of Ross Sea sequences reveals nature of ice sheet dynamics during the early to middle Miocene. (ID: 752). SCAR2020 OPEN SCIENCE CONFERENCE; Pérez, L.F. et al. Reviewed stratigraphy of the southern Scotia Sea basins (Antarctica): preliminary results on core-log-seismic integration from IODP Expedition 382. (ID: 529888). AMERICAN GEOPHYSICAL UNION - AGU Fall Meeting 2019]. She has been invited speaker in seminars at OGS, VUW, University of Tasmania, and Lamont-Doherty Earth Observatory – Columbia University.
The researcher has completed the training on the software Hampson Russell - Emerge and CAT3D during the secondment at OGS. She attended the Petrophysics Summer School 2019 at University of Leicester and a course on Petrel software at Royal Holloway University of London in UK. She has completed the British Antarctic Survey mandatory courses on Fraud e-Learning, Motivational Maps, General Data Protection Regulation, Taking Security Home: Working Remotely Training and 2020 Kevin Mitnick Security Awareness Training, as well as the optional The Inside Man mini series.
The researcher has been involved in the leadership of the Association of Polar Early Career Scientists as Council (2018-2019) and Executive Committee member (2019-2020). She has led the organization of several outreach activities including authorship of four outreach articles. She has mentored early career participants during 2019 AGU Fall Meeting. She has reviewed six manuscripts for international peer-review journals and assessed fellowship applications for five international calls.
The researcher has frequent meetings with collaborators and the three WAMSISE supervisors. Most of the meetings occur remotely via Zoom due to the COVID-19 restrictions.
The deliverables proposed within WP4 and WP5 are expected to be partly achieved. The expected manuscripts will be developed during the final year of the project. However, the COVID-19 limits the possibilities on conferences, workshops, training and outreach activities. This will severely impact the communication of the project results.
The researcher is also planning to continue training in Techlog software that has direct implications for WAMSISE research. However, the course availability depends on COVID-19 evolution.