Modification of the pattern informatics method for forecasting large earthquake events using complex eigenvectors

Recent studies have shown that real-valued principal component analysis can be applied to earthquake fault systems for forecasting and prediction. In addition, theoretical analysis indicates that earthquake stresses may obey a wave-like equation, having solutions with inverse frequencies for a given fault similar to those that characterize the time intervals between the largest events on the fault. It is therefore desirable to apply complex principal component analysis to develop earthquake forecast algorithms. In this paper we modify the Pattern Informatics method of earthquake forecasting to take advantage of the wave-like properties of seismic stresses and utilize the Hilbert transform to create complex eigenvectors out of measured time series. We show that Pattern Informatics analyses using complex eigenvectors create short-term forecast hot-spot maps that differ from hot-spot maps created using only real-valued data and suggest methods of analyzing the differences and calculating the information gain.Comment: 13 pages, 1 figure. Submitted to Tectonophysics on 30 August 200

Application of DInSAR-GPS optimization for derivation of fine-scale surface motion maps of Southern California

A method based on random field theory and Gibbs-Markov random fields equivalency within Bayesian statistical framework is used to derive 3-D surface motion maps from sparse global positioning system (GPS) measurements and differential interferometric synthetic aperture radar (DInSAR) interferogram in the southern California region. The minimization of the Gibbs energy function is performed analytically, which is possible in the case when neighboring pixels are considered independent. The problem is well posed and the solution is unique and stable and not biased by the continuity condition. The technique produces a 3-D field containing estimates of surface motion on the spatial scale of the DInSAR image, over a given time period, complete with error estimates. Significant improvement in the accuracy of the vertical component and moderate improvement in the accuracy of the horizontal components of velocity are achieved in comparison with the GPS data alone. The method can be expanded to account for other available data sets, such as additional interferograms, lidar, or leveling data, in order to achieve even higher accuracy

Slade, London, Asia: Contrapuntal Histories between Imperialism and Decolonization 1945–1989 (Part 1)

This feature takes the Slade School of Fine Art as the starting point for a global microhistory and reimagines ways of engaging with, co-constituting, and curating a research archive in pursuit of this endeavour. It consists of two parts: contributions in this issue of British Art Studies focus on the immediate post-war period, roughly 1945 to 1965, and a forthcoming second part will consider the 1960s to the 1990s. In this issue, the feature comprises a narrative history that interrogates the Slade’s role as a contrapuntal node, and a companion archival feature that brings together materials from multiple institutional and personal archives in Asia and the United Kingdom (UK). Building upon Edward Said’s use of the musical metaphor of contrapuntalism to address both the presence of empire in the metropolis and the construction of a transnational counterpoint with multiple voices, this project seeks to surface histories at the intersection of art education, imperialism, and decolonization. By using the Slade as a transversal line that connects multiple people and histories from Bangladesh, India, Pakistan, Hong Kong, Taiwan, Indonesia, Singapore, Nigeria, Sudan, Uganda, Britain and beyond, this essay proposes new ways of writing histories of contrapuntal—not multiple—modernisms, as well as understanding art in Britain itself as a product of empire

Worlding Art History through Syllabi

The recent ‘global turn’ in art history and curatorial practice has prompted the question of how to reflect this through pedagogy. The workshop Worlding Art History through Syllabi takes up the notion of ‘worlding’ to explore how art history is taught in different places and institutions around the world. What would a ‘worlded’ syllabus look like, and how can we collaboratively ‘world’ global art history? A ‘worlded’ art history rejects the idea of a single global world framed, ordered and represented according to Eurocentric premises or as universally constituted by global capitalism. Instead, it conceives of the global as constituted from multiple and entangled geo-cultural perspectives. It is not centered on assumed commonalities of ‘global’ art. Rather, it seeks to shed light on differences and relations. What are histories, epistemologies, and ontologies that constitute ‘global’ art? What are infrastructural or institutional incommensurabilities which define the many intersecting art histories of the present? This workshop invites scholars from the fields of art history, cultural studies, cultural anthropology, media studies, museum studies and other related disciplines to participate in an peer-to-peer exchange of experiences and practices. It focuses on how scholars may, or already have, designed teaching syllabi to complicate dominant frameworks of ‘global’ art history. It is particularly interested in how syllabi have the capacity to restructure pedagogical approaches to teaching topics such as global capitalism in the art world, the so-called Global North-South division, transnational and transcultural entanglements, and differences between teaching regional art histories.  Worlding Art History through Syllabi, workshop, ICI Berlin, 10–11 October 2022 <https://doi.org/10.25620/e221010

Earthquake forecasting and its verification

No proven method is currently available for the reliable short time prediction of earthquakes (minutes to months). However, it is possible to make probabilistic hazard assessments for earthquake risk. These are primarily based on the association of small earthquakes with future large earthquakes. In this paper we discuss a new approach to earthquake forecasting. This approach is based on a pattern informatics (PI) method which quantifies temporal variations in seismicity. The output is a map of areas in a seismogenic region (``hotspots'') where earthquakes are forecast to occur in a future 10-year time span. This approach has been successfully applied to California, to Japan, and on a worldwide basis. These forecasts are binary--an earthquake is forecast either to occur or to not occur. The standard approach to the evaluation of a binary forecast is the use of the relative operating characteristic (ROC) diagram, which is a more restrictive test and less subject to bias than maximum likelihood tests. To test our PI method, we made two types of retrospective forecasts for California. The first is the PI method and the second is a relative intensity (RI) forecast based on the hypothesis that future earthquakes will occur where earthquakes have occurred in the recent past. While both retrospective forecasts are for the ten year period 1 January 2000 to 31 December 2009, we performed an interim analysis 5 years into the forecast. The PI method out performs the RI method under most circumstances.Comment: 10(+1) pages, 5 figures, 2 tables. Submitted to Nonlinearl Processes in Geophysics on 5 August 200