Die neue Wiener Klinik für Kehlkopf und Nasenkrankheiten. Von Prof Dr Ottokar Chiari and Prof Dr Otto Kahler. Berlin and Vienna: Urban und Schwarzenberg, 1912.

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A note on estimating Te from Bouguer coherence

The coherence between Bouguer gravity anomalies and topography is widely used to estimate the value of Te, the effective elastic thickness of the lithosphere. In areas where there is little topography but substantial free air gravity anomalies there is often little coherence between the free air anomalies and topography. In such regions the Bouguer coherence method generally gives estimates of Te of 90 km or more. A detailed analysis shows that, under these conditions, the value of the Bouguer coherence γ2b is entirely controlled by the ratio of the power spectra of the free air gravity anomalies and the uncompensated topography, and contains no information about the value of Te. What is worse, under these circumstances the variation of γ2b with wavelength closely resembles that expected for large values of Te. These results show that neither the Bouguer coherence method nor the admittance method can produce meaningful estimates of Te when the free air gravity anomalies are incoherent with the topography

Subparallel thrust and normal faulting in Albania and the roles of gravitational potential energy and rheology contrasts in mountain belts

The active tectonics of Albania and surrounding regions, on the eastern margin of the Adriatic Sea, is characterized by subparallel thrust and normal faulting which, we suggest, is likely to be related to gravitational potential energy contrasts between the low-lying Adriatic Sea and the elevated mountainous areas inland. We calculate the magnitude of the force which the mountains and lowlands exert upon each other as a result of this potential energy contrast. It is likely that this force is largely supported by shear stresses on faults, and if so, the average stresses are less than ∼20 MPa. Alternatively, if the mountains are supported by stresses in the ductile part of the lithosphere, the stresses are likely to be ∼80–240 MPa in magnitude. The mountains of Albania are significantly lower than other ranges, such as the Peruvian Andes, which are thought to be extending in response to potential energy differences, and we discuss the relation between Albania and these other, higher, mountain belts from the perspective of differences in lithosphere rheology. We suggest that the lowlands of western Albania and the Adriatic Sea may have been weakened through time as a result of the deposition of large thicknesses of sediment, which lead to heating of the crystalline basement, a reduction in the potential energy contrast that could be supported by the lowlands, and so normal faulting in the mountains of eastern Albania

A crystallographic approach to symmetry-breaking in fluid layers

Symmetry-breaking bifurcations, where a flow state with a certain symmetry undergoes a transition to state with a different symmetry, are ubiquitous in fluid mechanics. Much can be understood about the nature of these transitions from symmetry alone, using the theory of groups and their representations. Here we show how the extensive databases on groups in crystallography can be exploited to yield insights into fluid-dynamical problems. In particular, we demonstrate the application of the crystallographic layer groups to problems in fluid layers, using thermal convection as an example. Crystallographic notation provides a concise and unambiguous description of the symmetries involved, and we advocate its broader use by the fluid dynamics community.Comment: 27 pages, 9 figures, 3 supplementary table

The structure of the lithosphere and upper mantle beneath the Eastern Mediterranean and Middle East

Funder: University of CambridgeAbstractSurface velocity measurements show that the Middle East is one of the most actively deforming regions of the continents. The structure of the underlying lithosphere and convecting upper mantle can be explored by combining three types of measurement. The gravity field from satellite and surface measurements is supported by the elastic properties of the lithosphere and by the underlying mantle convection. Three dimensional shear wave velocities can be determined by tomographic inversion of surface wave velocities. The shear wave velocities of the mantle are principally controlled by temperature, rather than by composition. The mantle composition can be obtained from that of young magmas. Application of these three types of observation to the Eastern Mediterranean and Middle East shows that the lithosphere thickness in most parts is no more than 50-70 km, and that the elastic thickness is less than 5 km. Because the lithosphere is so thin and weak the pattern of the underlying convection is clearly visible in the topography and gravity, as well as controlling the volcanism. The convection pattern takes the form of spokes: lines of hot upwelling mantle, joining hubs where the upwelling is three dimensional. It is the same as that seen in high Rayleigh number laboratory and numerical experiments. The lithospheric thicknesses beneath the seafloor to the SW of the Hellenic Arc and beneath the NE part of the Arabian Shield are more than 150 km and the elastic thicknesses are 30–40 km.</jats:p

A National Census of Sustainability in K-12 Education Policy: Implications for International Monitoring, Evaluation, and Research

This paper reports on the first nationwide census examining sustainability uptake in policy initiatives in Canadian K-12 education. Included in the study are each of Canada’s 13 provincial and territorial ministries of education, and all 374 public school divisions across the country. Sustainability was defined as including, at minimum, consideration of environmental issues, with the study also encompassing use of other related terminologies. Data were collected on three types of policy initiatives: (a) the existence of sustainability-specific policy, (b) participation in sustainability certification programs, and (c) the existence of sustainability staff, which were examined in relation to a range of geographic and institutional variables. Sustainability-specific policy was examined across five domains of a whole institution approach to sustainability: governance, curriculum, facilities and operations, research, and community outreach. We found that 54% of ministries of education and 59% of school divisions in Canada had sustainability-specific policy, most commonly in the curriculum domain at the ministry level and in the operations domain at the school division level. In addition, 43% of school divisions had participated in a sustainability certification program, and 25% had sustainability staff. We discuss implications for policy making in Canada as well for intergovernmental UN policy programs, in particular regarding new policy development and monitoring and evaluation efforts

The lithospheric structure of Pangea

Lithospheric thickness of continents, obtained from Rayleigh wave tomography, is used to make maps of the lithospheric thickness of Pangea by reconstructing the continental arrangement in the Permian. This approach assumes that lithosphere moves with the overlying continents, and therefore that the arrangement of both can be obtained using the poles of rotation obtained from magnetic anomalies and fracture zones. The resulting reconstruction shows that a contiguous arc of thick lithosphere underlay most of eastern Pangea. Beneath the western convex side of this arc, there is a wide belt of thinner lithosphere underlying what is believed to have been the active margin of Pangea, here named the Pangeides. On the inner side of this arc is another large area of thin lithosphere beneath the Pan-African belts of North Africa and Arabia. The arc of thick lithosphere is crossed by bands of slightly thinner lithosphere that lie beneath the Pan-African and Brasiliano mobile belts of South America, Africa, India, Madagascar, and Antarctica. This geometry suggests that lithospheric thickness has an important influence on continental deformation and accretion

A History of Supra-Arcade Downflows and Their Connection to Reconnection

No abstract availabl