Resurvey of site stability quadrilaterals, Otay Mountain and Quincy, California

Trilateration quadrilaterals established across two faults near the San Andreas Fault Experiment laser/satellite ranging sites were resurveyed after four years. No evidence of significant tectonic motion was found

Surface deformation and elasticity studies in the Virgin Islands

The report consists of four sections. The first section describes tilt and leveling measurements on Anegada, the most northerly of the British Virgin Islands; the second section contains a discussion of sea-level measurements that were initiated in the region and which played a significant role in the development of a network of sea-level monitors now telemetered via satellite from the Alaskan Shumagin Islands. The third part of the report is a brief description of surface deformation measurements in Iceland using equipment and techniques developed by the subject grant. The final part of the report describes the predicted effects of block surface fragmentation in tectonic areas on the measurement of tilt and strain

Theory of time-dependent rupture in the Earth

Fracture mechanics is used to develop a theory of earthquake mechanism which includes the phenomenon of subcritical crack growth. The following phenomena are predicted: slow earthquakes, multiple events, delayed multiple events (doublets), postseismic rupture growth and afterslip, foreshocks, and aftershocks. The theory predicts a nucleation stage prior to an earthquake, and suggests a physical mechanism by which one earthquake may 'trigger' another

Metamorphism, argon depletion, heat flow and stress on the Alpine fault

The Alpine fault of New Zealand is a major continental transform fault which was uplifted on its southeast side 4 to 11 km within the last 5 m.y. This uplift has exposed the Haast schists, which were metamorphosed from the adjacent Torlesse graywackes. The Haast schists increase in metamorphic grade from prehnite-pumpellyite facies 9-12 km from the fault through the chlorite and biotite zones of the greenschist facies to the garnet-oligoclase zone amphibolite facies within 4 km of the fault. These metamorphic zone boundaries are subparallel to the fault for 350 km along the strike. The K-Ar and Rb-Sr ages of the schists increase with distance from the fault: from 4 m.y. within 3 km of the fault to approximately 110 m.y. 20 km from the fault. Field relations show that the source of heat that produced the argon depletion aureole was the fault itself

Strain buildup and release, earthquake prediction and selection of VLB sites for the margins of the North Pacific

Projects studying different aspects of crustal deformation are discussed. The rifting process at the plate boundary in northern Iceland was investigated using combined seismic, tilt, and displacement measurements. Stresses acting on the Alpine fault, New Zealand, were modeled based on observations of regional variation in metamorphism and argon loss. The relationship between the stress pattern shown by intraplate seismicity and possible stresses on plates arising from litohspheric motion over the asthenosphere was investigated. Small earthquakes in Southern California were studied to determine if subregions of uniform strain release exist and if interaction occurs between faults

On the Predictability of Talk Attendance at Academic Conferences

This paper focuses on the prediction of real-world talk attendances at academic conferences with respect to different influence factors. We study the predictability of talk attendances using real-world tracked face-to-face contacts. Furthermore, we investigate and discuss the predictive power of user interests extracted from the users' previous publications. We apply Hybrid Rooted PageRank, a state-of-the-art unsupervised machine learning method that combines information from different sources. Using this method, we analyze and discuss the predictive power of contact and interest networks separately and in combination. We find that contact and similarity networks achieve comparable results, and that combinations of different networks can only to a limited extend help to improve the prediction quality. For our experiments, we analyze the predictability of talk attendance at the ACM Conference on Hypertext and Hypermedia 2011 collected using the conference management system Conferator

Substellar Objects in Nearby Young Clusters (SONYC) IX: The planetary-mass domain of Chamaeleon-I and updated mass function in Lupus-3

Substellar Objects in Nearby Young Clusters -- SONYC -- is a survey program to investigate the frequency and properties of substellar objects in nearby star-forming regions. We present new spectroscopic follow-up of candidate members in Chamaeleon-I (~2 Myr, 160 pc) and Lupus 3 (~1 Myr, 200 pc), identified in our earlier works. We obtained 34 new spectra (1.5 - 2.4 mum, R~600), and identified two probable members in each of the two regions. These include a new probable brown dwarf in Lupus 3 (NIR spectral type M7.5 and Teff=2800 K), and an L3 (Teff=2200 K) brown dwarf in Cha-I, with the mass below the deuterium-burning limit. Spectroscopic follow-up of our photometric and proper motion candidates in Lupus 3 is almost complete (>90%), and we conclude that there are very few new substellar objects left to be found in this region, down to 0.01 - 0.02 MSun and Av \leq 5. The low-mass portion of the mass function in the two clusters can be expressed in the power-law form dN/dM \propto M^{-\alpha}, with \alpha~0.7, in agreement with surveys in other regions. In Lupus 3 we observe a possible flattening of the power-law IMF in the substellar regime: this region seems to produce fewer brown dwarfs relative to other clusters. The IMF in Cha-I shows a monotonic behavior across the deuterium-burning limit, consistent with the same power law extending down to 4 - 9 Jupiter masses. We estimate that objects below the deuterium-burning limit contribute of the order 5 - 15% to the total number of Cha-I members.Comment: Accepted for publication by Astrophysical Journa