Implications of fault constitutive properties for earthquake prediction.

The rate- and state-dependent constitutive formulation for fault slip characterizes an exceptional variety of materials over a wide range of sliding conditions. This formulation provides a unified representation of diverse sliding phenomena including slip weakening over a characteristic sliding distance Dc, apparent fracture energy at a rupture front, time-dependent healing after rapid slip, and various other transient and slip rate effects. Laboratory observations and theoretical models both indicate that earthquake nucleation is accompanied by long intervals of accelerating slip. Strains from the nucleation process on buried faults generally could not be detected if laboratory values of Dc apply to faults in nature. However, scaling of Dc is presently an open question and the possibility exists that measurable premonitory creep may precede some earthquakes. Earthquake activity is modeled as a sequence of earthquake nucleation events. In this model, earthquake clustering arises from sensitivity of nucleation times to the stress changes induced by prior earthquakes. The model gives the characteristic Omori aftershock decay law and assigns physical interpretation to aftershock parameters. The seismicity formulation predicts large changes of earthquake probabilities result from stress changes. Two mechanisms for foreshocks are proposed that describe observed frequency of occurrence of foreshock-mainshock pairs by time and magnitude. With the first mechanism, foreshocks represent a manifestation of earthquake clustering in which the stress change at the time of the foreshock increases the probability of earthquakes at all magnitudes including the eventual mainshock. With the second model, accelerating fault slip on the mainshock nucleation zone triggers foreshocks.

Dynamic friction and the origin of the complexity of earthquake sources.

We study a simple antiplane fault of finite length embedded in a homogeneous isotropic elastic solid to understand the origin of seismic source heterogeneity in the presence of nonlinear rate- and state-dependent friction. All the mechanical properties of the medium and friction are assumed homogeneous. Friction includes a characteristic length that is longer than the grid size so that our models have a well-defined continuum limit. Starting from a heterogeneous initial stress distribution, we apply a slowly increasing uniform stress load far from the fault and we simulate the seismicity for a few 1000 events. The style of seismicity produced by this model is determined by a control parameter associated with the degree of rate dependence of friction. For classical friction models with rate-independent friction, no complexity appears and seismicity is perfectly periodic. For weakly rate-dependent friction, large ruptures are still periodic, but small seismicity becomes increasingly nonstationary. When friction is highly rate-dependent, seismicity becomes nonperiodic and ruptures of all sizes occur inside the fault. Highly rate-dependent friction destabilizes the healing process producing premature healing of slip and partial stress drop. Partial stress drop produces large variations in the state of stress that in turn produce earthquakes of different sizes. Similar results have been found by other authors using the Burridge and Knopoff model. We conjecture that all models in which static stress drop is only a fraction of the dynamic stress drop produce stress heterogeneity.

Gazprom's expansion in the EU - co-operation or domination? OSW Report, April 2008

The energy sector, especially with regard to natural gas trade, is one of the key areas of co-operation between the EU and Russia. However, the character of this co-operation has given rise to increasing doubts both in Brussels and among the EU member states. The questions have emerged whether this co-operation does not make the EU excessively dependent on Russian energy supplies, and whether Gazprom's presence in the EU will not allow Moscow to interfere in the proces of devising the EU energy policy. This report is intended to present the factual base and data necessary to provide accurate answers to the foregoing questions. The first part of the report presents the scope and character of Gazprom's economic presence in the EU member states. The second part shows the presence of the EU investors in Russia. The data presented has been provided by the International Energy Agency, European Commission, the Central Bank of Russia and the Russian Federal State Statistics Service. Some of the data is the result of calculations made by the Centre for Eastern Studies' experts who were basing on the data provided by energy companies, the specialist press and news agencies.

Civil service and libraries /

Bibliography: p. 37-40.

Annual report - Department of Civil Service and Civil Service Commission.

Report for 1909 includes "Civil list of the state, county and village service classified under the state civil service rules. July 1, 1910."

Funds for research at State agricultural experiment stations and other State institutions.

1895/96 not published; 1896/97 issued as S. doc. 137, 54th Cong., 2d sess., serial no. 3470; 1896/97-1900/1901 issued as U. S. Office of Experiment Stations, Bulletin no. 50, 61, 83, 93; 1914/15-1916/17 published as pt. I of Report on experiment stations and extension work in the United States; 1953/54-1963/64 issued as U. S. Cooperative State Research Service. CSRS-23, no. 1 [etc.]; 1964/65- as U. S. Cooperative State Research Service. CSRS-15, no no. 1 [etc.]

Bees and other pollinating insects research : a directory of USDA and state projects in CRIS /

"June 1987."

Aquaculture research : a directory of USDA and state projects in CRIS /

Mode of access: Internet.

Report of investigation of the financial condition of the railroads operating in the State of New York,

Mode of access: Internet.

Training manual for employment service personnel /

WI docs no.: EMP 6/2:1938

History of the public employment service in Wisconsin.

WI docs no.: EMP 2.2:H 5

Monthly statistical bulletin of the Unemployment Compensation Division and the Employment Service Division.

Issues for Jan.- 1939 called v. 1, no. 1-

A civil service manual /

"April 2, 1937."

Working for the Secretary of State.

Mode of access: Internet.

Maryland weather service. [Reports. New ser.] v. 1-3.

Earlier reports have title: The climatology and physical features of Maryland. First [-second] biennial report of the Maryland state weather service 1892/93-1894/95.