A correlation study between ozone and volcanic activity

A cross-correlation study for time-lags of ±5 yrs between eleven ground based ozone stations (1957-1985) for φ{symbol} = 40°N-75° N and λ = 30° E-114° W and five volcanic emissivity indices has shown their close connection: significant correlations well above 90% were obtained. Intepretation of these positive/negative correlations (γ) was based on the global wind circulation (aided also by a 2-D, 3-D representation between φ{symbol}, λ, γ), and the types of volcanic aerosols leading to heterogeneous chemical reactions with ozone. © 1994 Kluwer Academic Publishers

Geoelectric investigation of the Hellenic subduction zone using long period magnetotelluric data

The strongest evidence up to date for a subduction zone in the Hellenic region is a clearly identified Wadati-Benioff zone below the central Aegean Sea, to a maximum depth of 180 km. Alternative seismic tomography models suggest that subduction process continues deeper than the Wadati-Benioff zone to a maximum depth of at least 600 km. So far the lack of deep electrical studies in the region impeded scientists from imposing other control factors than seismic to the proposed models for the Hellenic Subduction Zone (HSZ). A Long Period Magnetotelluric (LMT) study was carried out in the southern part of the Greek mainland to study the deep electrical characteristics of the HSZ and examine whether prominent modelled features correlate with structures identified by the seismic methods. The study comprised collection, processing and modelling of magnetotelluric (MT) data in the period range 100-10000 s from ten sites located along a 250 km NE-SW trending profile. The dimensionality of the data was examined at a pre-modelling stage and it was found that they do not exhibit three-dimensional (3-D) features. The latter enabled to construct both one-dimensional (1-D) and two-dimensional (2-D) models. The proposed geoelectric model for HSZ was based on 2-D modelling, since it had better maximum depth resolution of about 400 km, and revealed structures not detected by 1-D modelling attempts. The model structure which was related to the African and Euro-Asian lithosphere is relatively resistive (>800 Ω-m) and has an average thickness of 150-170 km. Although the bottom of the lithosphere is adequately resolved, the Wadati-Benioff zone that delineates the top of the subducting lithospheric slab is not identified by any electrical feature. The modelled structure associated with the subducting part of the African lithosphere penetrates a relatively conductive (<200 Ω-m) asthenosphere with a dip angle of 42°. Intermediate electrical resistivities (200-800 Ω-m) are attributed to the ascending melting part of the lithosphere below the region of the Hellenic Volcanic Arc (HVA) and to a dipping zone below the south-western part of the profile, at 170-220 km depths. © 2005 Elsevier B.V. All rights reserved

Lady farmerette Miss May Hodgson tending to horses outside stables, Moss Vale, New South Wales, 15 October 1931 [picture].

Title devised from accompanying information where available.; Part of the: Fairfax archive of glass plate negatives.; Fairfax number: 4574 ; 3203.; Photographed by Robinson; Also available online at: http://nla.gov.au/nla.pic-vn6251080; Acquired from Fairfax Media, 2012