SensePlace3: a geovisual framework to analyze place–time–attribute information in social media

SensePlace3 (SP3) is a geovisual analytics framework and web application that supports overview + detail analysis of social media, focusing on extracting meaningful information from the Twitterverse. SP3 leverages social media related to crisis events. It differs from most existing systems by enabling an analyst to obtain place-relevant information from tweets that have implicit as well as explicit geography. Specifically, SP3 includes not just the ability to utilize the explicit geography of geolocated tweets but also analyze implicit geography by recognizing and geolocating references in both tweet text, which indicates locations tweeted about, and in Twitter profiles, which indicates locations affiliated with users. Key features of SP3 reported here include flexible search and filtering capabilities to support information foraging; an ingest, processing, and indexing pipeline that produces near real-time access for big streaming data; and a novel strategy for implementing a web-based multi-view visual interface with dynamic linking of entities across views. The SP3 system architecture was designed to support crisis management applications, but its design flexibility makes it easily adaptable to other domains. We also report on a user study that provided input to SP3 interface design and suggests next steps for effective spatiotemporal analytics using social media sources.     

Internal Boundary Layers: I. Height Formulae for Neutral and Diabatic Flows

The notion of an internal boundary layer (IBL) appeared in studies of local advection within the atmospheric boundary layer when air flows over a change in surface conditions. These include surface roughness, thermal and moisture properties. An ability to predict the height of the IBL interface in the atmosphere under neutral stability, accompanied by certain assumptions on the form of the mean flow parameters, have been a means of obtaining information on the velocity profile after step changes in roughness for more than half a century. A compendium of IBL formulae is presented. The approach based on the diffusion analogy of Miyake receives close attention. The empirical expression of Savelyev and Taylor (2001, Boundary Layer Meteorol. 101, 293–301) suggested that turbulent diffusion is not the only factor that influences IBL growth. An argument is offered that an additional element, mean vertical velocity or streamline displacement, should be taken into account. Vertical velocity is parameterized in terms of horizontal velocity differences employing continuity constraints and scaling. Published data are analyzed from a new point of view, which produces two new neutral stratification formulae. The first implies that the roughness lengths of adjacent surfaces are equally important and a combined length scale can be constructed. In addition new formulae to predict the height of the region of diabatic flow affected by a step change in surface conditions are obtained as an extension of the neutral flow case.     

First Find of Platinum in Cosmogenic Spherules of Ferromanganese Crusts (Fedorov Guyot,Magellan Seamounts,Pacific Ocean)

Doklady Earth Sciences - More than 250 magnetic spherules 40–200 µm in size were mechanically separated from a ferromanganese crust sample of Fedorov Guyot in the Magellan Seamounts. The...     

Plagioclase picrites in the Kamchatsky Mys Peninsula,Eastern Kamchatka

The zone of serpentinite melange in the Kamchatsky Mys Peninsula was found to contain high-magnesium ultramafic volcanic rocks, viz., plagioclase picrite (oceanite) with a MgO concentration of 22.5–25.8%. We evaluated the petrochemical and geochemical characteristics of these rocks, as well as their mineral compositions. The olivine phenocrysts make up 50–60% of the rock volume; their composition (mostly 87–89 mol % Fo) and the composition of melt inclusions in them indicate their origin from a picritic melt with an additional cumulative enrichment in olivine. The geochemical parameters (Zr/Y = 3.1, Th/Yb = 0.14–0.18, Nb/Yb = 2.39–2.66, La_(N)/Sm_(N) = 1.0–1.1, La_(N)/Yb_(N) = 1.24–1.42) indicate an oceanic genesis of these rocks affected by a mantle plume.     

Tectonostratigraphic complexes of the southern Kronotskii paleoarc (Eastern Kamchatka): Structure,age, and composition

The eastern peninsulas of Kamchatka are mostly composed of tectonostratigraphic complexes, which were formed within the Late Cretaceous-Eocene Kronotskii-Kamchatka arc. The accretion of this paleoarc to the Kamchatka margin of northeastern Asia in the terminal Cenozoic represented the last collisional event in the formation of the present-day structure of Kamchatka. The article presents new data on the age, composition, and structure of the tectonostratigraphic complexes constituting the southern segment of the Kronotskii-Kamchatka paleoarc. It is shown that the oldest rocks of these complexes are the Campanian in age and represented by volcano-sedimentary rocks that were formed in different geodynamic environments. The investigated igneous rocks are attributed to two types: (1) the tholeiite series of a mid-oceanic ridge (MOR) (Vetlovaya Complex); (2) tholeiite and calc-alkaline series of island arcs (Shipunskii Sequence of the Kronotskii Group).     

The source of platinum group elements in basalts of the ophiolite complex of the Kamchatsky Mys Peninsula (Eastern Kamchatka)

Contents of platinum group elements (PGE—Os, Ir, Ru, Rh, Pt, and Pd) and rhenium in basalts of different geochemical types from the ophiolite complex of the Kamchatsky Mys Peninsula have been determined by the isotope dilution-mass spectrometry method. The total contents of PGE in different basalts are commensurate (1.4-3.6 ppb), but the element ratios vary considerably. A specific feature of the rocks is the low degree of PGE fractionation (Pd/Ir = 0.9-6.6, Pt/Pd = 1.0-7.3), which makes them similar to the Hawaiian tholeiitic basalts and picrites. The most fractionated PGE pattern is observed for alkali basalt (Pd/Ir = 6.6), and the least fractionated one, for E-MORB (Pd/Ir = 1.7). The similarity of the PGE patterns of basalts of different geochemical types suggests their similar mantle sources. We propose a model explaining the geochemical features of the basalts of the Kamchatsky Mys ophiolite complex by an impurity of the Earth’s core material in the plume source. The Ir/Pd-Ru/Pd and Pd/10-Ir-Ru discrimination diagrams can be used to identify enriched (plume) basalts based on their PGE content.     

Notes on an Internal Boundary-Layer Height Formula

The derivation of the Panofsky–Dutton internal boundary-layer(IBL) height formula has been revisited. We propose that the upwindroughness length (rather than downwind) should be used in theformula and that a turbulent vertical velocity (_w) ratherthan the surface friction velocity (u_*) should be considered asthe appropriate scaling for the rate of propagation ofdisturbances into the turbulent flow. A published set ofwind-tunnel and atmospheric data for neutral stratification hasbeen used to investigate the influence of the magnitude ofroughness change on the IBL height.