Suchergebnisse

The multifractal detrended fluctuation algorithm is applied to a series of distances and elapsed times between consecutive earthquakes recorded along the years 2000–2018 in the Canterbury region (New Zealand). The time evolution of several multifractal parameters (Hurst exponent, Hölder central and maximum exponents, spectral amplitude, asymmetry, and complexity index) is analyzed. Peaks of multifractal parameters, with statistical significance exceeding 95%, are associated with three earthquakes of notable magnitude (equaling or exceeding Mw = 5.7). Additionally, some other peaks are also associated with the swarm of earthquakes of moderate magnitude. Possible shortcomings created by this assignment to mainshocks or swarms can be removed by comparing the results corresponding to elapsed times and interevent distances between consecutive events. Additionally, the Buishand test, which is used to verify the statistical significance of the detected peaks, also discriminates between mainshocks of notable seismic magnitude and swarms of earthquakes with moderate magnitude. The obtained results, based on the multifractal structure of the seismic activity, could also represent some advances in predicting, with sufficient time, forthcoming mainshocks of high magnitude and mitigate their destructive effects. ; The research leading to these results has received funding from the European Union's Horizon 2020 research and innovation program, under Grant Agreement No. 823844, the ChEESE CoE Project. ; Peer Reviewed ; Postprint (published version)

The pluviometric regime in the Western Mediterranean and concretely in Catalonia (NE Spain) is characterised by irregular amounts at monthly and annual scales, sometimes with copious short episodes causing foods and, conversely, sometimes with long dry spells exceeding 1 month length, depending on the chosen threshold level to defne the dry episode. Taking advantage of a dense network of rain gauges, most of them with records length of 50–60 years and some others exceeding 85 years, the evolution of these monthly and annual amounts is quantifed by means of their time trends, statistical signif- cance and several irregularity parameters. In agreement with the evolution of the CO2 emissions into the atmosphere and the increasing concentration, in parts per million (ppm), of this greenhouse gas, diferent time trends at annual scale have been detected up to approximately years 1960–1970 in comparison with the interval 1960–1970 to nowadays. Consequently, besides the greenhouse efects on the temperature regime, the infuence on the pluviometric regime could not be negligible. ; Rainfall data have been supplied by Servei Mete‑ orològic de Catalunya (Generalitat de Catalunya), Fabra Observatory (RACA, Barcelona) and Ebro Observatory (Ramón Llull University and CSIC, Spanish Government). This research was supported by the Spanish Ministry of Science, Innovation and Universities: grant 460 number PID2019-105976RB-I00] and grant number AGL201787658-R. The authors also thank the editor and the anonymous reviewers for their valuable comments and suggestions to improve the manuscript ; Peer Reviewed ; Postprint (published version)