Pre-eruption magma staging at the long-lived intraplate Dunedin Volcano, New Zealand

Funder: NZ Federation of Graduate WomenFunder: University of Otago; Id: http://dx.doi.org/10.13039/100008247Abstract: The oldest‐known rocks of the eroded Dunedin Volcano (DV), New Zealand, active 16.0–11.0 Ma, were emplaced by penecontemporaneous explosive eruptions and intrusions of magmas with a remarkable range of compositions, including basanite, alkali basalt, trachyte and phonolite. The compositional diversity of magmas emplaced in rapid succession during the earliest development of the volcano signify the existence of a complex magmatic system and highly evolved magmas, typical of those attributed to mature magmatic systems; here it developed in concert with the volcano's surface eruptions. We infer that multiple deep and shallow reservoirs were suddenly tapped as volcanism commenced. DV repeatedly erupted the same range of magmas over 5 Myr, suggests that these distributed reservoirs failed to significantly integrate through millions of years of slow volcano growth

How to Measure Speech Recognition Performance in the Air Traffic Control Domain? The Word Error Rate is only half of the truth

Applying Automatic Speech Recognition (ASR) in the domain of analogue voice communication between air traffic controllers (ATCo) and pilots has more end user requirements than just transforming spoken words into text. It is useless, when word recognition is perfect, as long as the semantic interpretation is wrong. For an ATCo it is of no importance if the words of greeting are correctly recognized. A wrong recognition of a greeting should, however, not disturb the correct recognition of e.g. a “descend” command. Recently, 14 European partners from Air Traffic Management (ATM) domain have agreed on a common set of rules, i.e., an ontology on how to annotate the speech utterance of an ATCo. This paper first extends the ontology to pilot utterances and then compares different ASR implementations on semantic level by introducing command recognition, command recognition error, and command rejection rates. The implementation used in this paper achieves a command recognition rate better than 94% for Prague Approach, even when WER is above 2.5

Antarctic Environmental Change and Ice Sheet Evolution through the Miocene to Pliocene ¿ A perspective from the Ross Sea and George V to Wilkes Land Coasts

We wish to acknowledge the support of National Antarctic Programmes and the International Scientific Drilling Programmes and Projects that have allowed our community to acquire the critical records of environmental change that have been discussed in this review. We thank Jenny Black, GNS Science, for her assistance with Fig. 9.2. R.L., T.N., R.M., C.O. and N.G. acknowledge funding support from the New Zealand Ministry of Business and Innovation and Employment through the Antarctic Science Platform contract (ANTA1801) Antarctic Ice Dynamics Project (ASP-021-01). C.E. acknowledges funding by the Spanish Ministry of Economy, Industry and Competitivity (grant CTM2017-89711-C2-1/2-P), co-funded by the European Union through FEDER funds. L.F.P. was funded through the European Union’s Horizon 2020 research and innovation program under the Marie Sklodowska-Curie grant agreement number 792773 for the West Antarctic Margin Signatures of Ice Sheet Evolution (WAMSISE) Project

Sensitivity of the West Antarctic Ice Sheet to +2 °C (SWAIS 2C)

The West Antarctic Ice Sheet (WAIS) presently holds enough ice to raise global sea level by 4.3 m if completely melted. The unknown response of the WAIS to future warming remains a significant challenge for numerical models in quantifying predictions of future sea level rise. Sea level rise is one of the clearest planet-wide signals of human-induced climate change. The Sensitivity of the West Antarctic Ice Sheet to a Warming of 2 ∘C (SWAIS 2C) Project aims to understand past and current drivers and thresholds of WAIS dynamics to improve projections of the rate and size of ice sheet changes under a range of elevated greenhouse gas levels in the atmosphere as well as the associated average global temperature scenarios to and beyond the +2 ∘C target of the Paris Climate Agreement. Despite efforts through previous land and ship-based drilling on and along the Antarctic margin, unequivocal evidence of major WAIS retreat or collapse and its causes has remained elusive. To evaluate and plan for the interdisciplinary scientific opportunities and engineering challenges that an International Continental Drilling Program (ICDP) project along the Siple coast near the grounding zone of the WAIS could offer (Fig. 1), researchers, engineers, and logistics providers representing 10 countries held a virtual workshop in October 2020. This international partnership comprised of geologists, glaciologists, oceanographers, geophysicists, microbiologists, climate and ice sheet modelers, and engineers outlined specific research objectives and logistical challenges associated with the recovery of Neogene and Quaternary geological records from the West Antarctic interior adjacent to the Kamb Ice Stream and at Crary Ice Rise. New geophysical surveys at these locations have identified drilling targets in which new drilling technologies will allow for the recovery of up to 200 m of sediments beneath the ice sheet. Sub-ice-shelf records have so far proven difficult to obtain but are critical to better constrain marine ice sheet sensitivity to past and future increases in global mean surface temperature up to 2 ∘C above pre-industrial levels. Thus, the scientific and technological advances developed through this program will enable us to test whether WAIS collapsed during past intervals of warmth and determine its sensitivity to a +2 ∘C global warming threshold (UNFCCC, 2015)

Late Neogene evolution of the Antarctic cryosphere as derived from paleo- and environmental- magnetic studies of New Harbour drill cores

The Pliocene period is an attractive geological analogue from which to study the future behaviour of the cryosphere because global temperatures and atmospheric CO2 were inline with what is projected in the coming decades. A Pliocene succession recovered beneath the McMurdo Ice Shelf revealed repeated collapses of the West Antarctic Ice Sheet during the Pliocene period. This conflicts with geomorphic records from the Transantarctic Mountains, which have been used to argue for continued polar conditions since the middle Miocene. The New Harbour drill cores were examined because they contain Plio- Pleistocene sediments that were deposited in deep fiords located within the Transantarctic Mountains only a few kilometres from geomorphic records that were used to argue for stable polar conditions. New paleomagnetic age models were constructed for the core successions from AF and thermal demagnetisation of 559 specimens. Environmental magnetic records, which are sensitive indicators of the terrestrial climate evolution, were constructed for the drill core successions. In a parallel study, a database of the magnetic mineralogy of southern Victoria Land basement and cover rocks was compiled. The database was used to construct a model of the source to sink evolution of magnetic minerals and to identify how the modern climate is expressed in the offshore environmental magnetic records. The new age models indicate that the Taylor Glacier was thick and dynamic during latest Miocene and earliest Pliocene and that it retreated after 4.69 Ma. Maghemite and pure magnetite cycles between ∼4.9 Ma and ∼4.6 Ma in sediments are coherent with advance and retreat history of the Taylor Glacier. The presence of maghemite may indicate paedogenesis during interglacial periods under warmer and wetter conditions than today. Glaciers in the Taylor and Ferrar fiords retreated after ∼4.4 Ma resulting in the deposition of fine-grained sediments with very low magnetic concentrations. Magnetic mineralogy cycles are in phase with the benthic δ18O record and an up-core increase of coercivity may indicate greater input of terrigenous sediment by rivers. Evidence of terrestrial soil formation and ice-free fiords conflicts with the nearby contemporaneous geomorphic records used to argue for persistent hyper arid, modern style polar conditions. Significant unconformities after ∼4.2 Ma indicate a dynamic environment which agrees with the terrestrial geomorphic records of expansion of EAIS glaciers. Grounded eastern sourced ice entered New Harbour at 2.6 Ma and the appearance of paramagnetism in sediments may indicate a shift to a modern style climate and the onset of strong katabatic winds. A shift to sand dominated lithologies after ∼1.2 Ma indicates deposition in ice-dammed lakes during glacial maxima. Environmental magnetic behaviour of these sediments is identical to the behaviour of modern sediments from southern Victoria Land. The new chronologies of New Harbour successions demonstrate coherence between the emplacement age of the geomorphic features and unconformities in the drill cores, which were both caused by expansion of EAIS glaciers during the mid Pliocene. However, indications from New Harbour successions of much warmer than present conditions and deep, ice-free fiords conflict with contemporaneous evidence from the Dry Valleys of hyper polar conditions. It is possible that the geomorphic records are not sensitive indicators of climate evolution