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Tuairisc Bhliantúil 2022 Institiúid Ard-Léinn Bhaile Átha Cliath. Communications of the Dublin Institute for Advanced Studies.
Full text linkContributing to the sustainability of our world
Full text linkIn 2018, the Dublin Institute for Advanced Studies made a commitment to the United Nations Sustainable Development Goals (SDGs) in its strategy “Embedded globally, strength locally”.
Under the strategic goal – International research collaboration benefitting Ireland and the world, DIAS has an objective to “Leverage our excellence and international connectedness, and explore opportunities to contribute through research to the Sustainable Development Goals (SDGs)”.
On Earth Day (08 April 2022) DIAS published “Contributing to the sustainability of our world” – a statement highlighting the work DIAS has done since 2018, and continues to do, in support of the SDGs
Wind/WAVES observations of Auroral Kilometric Radiation: automated burst detection and Terrestrial Solar Wind - Magnetosphere coupling effects
Full text linkAuroral Kilometric Radiation (AKR) is the strongest terrestrial radio emission, and emanates from the same electron acceleration regions from which particles precipitate into the ionosphere, exciting the aurorae and other phenomena. As such, AKR is a barometer for the state of solar wind - magnetosphere - ionosphere coupling. AKR is anisotropically beamed in a hollow cone from a source region generally found at nightside local times, meaning that a single source region cannot be viewed from all local times in the magnetosphere. In radio data such as dynamic spectra, AKR is frequently observed simultaneously to other radio emissions which can have a similar intensity and frequency range, making it difficult to automatically detect. Building on a previously published pipeline to extract AKR emissions from Wind/WAVES data, in this paper a novel automated AKR burst detection technique is presented and applied again to Wind/WAVES data. Over a five year interval, about 5000 AKR bursts are detected with median burst length ranging from about 30-60 minutes. During detected burst windows, higher solar wind velocity is observed, and the interplanetary magnetic field (IMF) clock angle is observed to tend towards BZ<0, BY<0, when compared with the entire statistical interval. Additionally, higher geomagnetic activity is observed during burst windows at polar, high and equatorial latitudes
A new integrated geophysical-petrological global 3-D model of upper-mantle electrical conductivity validated by the Swarm M2 tidal magnetic field
Full text linkThe stability criterion for downward continuation of surface gravity data with various spatial resolutions over Ireland
Full text linkDuanaire i láimh an údair: Filíocht Eoghain Ruaidh Mhic an Bhaird i Leabhar Inghine Í Dhomhnaill
Full text linkThe tilted Iceland Plume and its effect on the North Atlantic evolution and magmatism
Full text linkIceland and the encompassing Northeast Atlantic are characterized by abun- dant volcanism, anomalously high topography and, in many places, anoma- lously thick basaltic crust. This has been attributed to the Iceland Plume, rising from the deep mantle, though its structure and very existence are de- bated. Using seismic waveform tomography with massive datasets, we compute a new, detailed model of the crust and upper mantle beneath Iceland and the surrounding North Atlantic region. The model reveals a large, low-velocity anomaly, indicative of high temperatures, at 400-660 kilometers depth beneath eastern Greenland, where seismic receiver functions also indicate an extensive high-temperature region. The anomaly rises upwards and eastwards toward Ice- land, deflecting around the thick lithosphere of Greenland’s cratons, which we also image in detail. We interpret the major low-velocity anomaly as the Ice- land Plume, ascending from under Greenland and captured by the Mid-Atlantic Ridge. The ascent of the plume beneath the western Northeast Atlantic is con- sistent with its thin lithosphere, documented by our tomography, and abundant seamounts. Our results reconcile previously contrasting views on the structure of the Iceland Plume: while the plume is clearly visible in the transition zone beneath Greenland, it is confined to the upper mantle beneath Iceland
Search result for "retrieving reflection arrivals from passive seismic data using radon correlation"
Full text linkSince explosive and impulsive seismic sources such as dynamite, air guns, gas guns, or even vibroseis can have a big impact on the environment, some companies have decided to record ambient seismic noise and use it to estimate the physical properties of the subsurface. Big challenges arise when the aim is extracting body-waves from recorded passive signals, especially in the presence of strong surface waves. In passive seismic signals, such body-waves are usually weak in comparison to surface waves which are much more prominent. To understand the characteristics of passive signals and the effect of natural source locations, three simple synthetic models were created. To extract body-waves from simulated passive signals we propose and test a Radon-correlation method. This is a time-spatial correlation of amplitudes with a train of time-shifted Dirac delta functions through different hyperbolic paths. It is tested on a two-layer horizontal model, three-layer model which includes a dipping layer (with and without lateral heterogeneity) and also on synthetic Marmousi model data sets. Synthetic tests show that the introduced method is able to reconstruct reflection events at the correct time-offset positions which are hidden in results obtained by the general cross-correlation method. Also, a depth migrated section shows a good match between imaged-horizons and the true model. It is possible to generate off-end virtual gathers by applying the method to a linear array of receivers and to construct a velocity model by semblance velocity analysis of individually extracted gathers