Category: Events

Potential Locations of Strong Earthquakes in Bulgaria and the Neighbouring Regions

Information about potential earthquake sources is a key issue for seismic hazard assessment. This study presents the application of a phenomenological approach based on pattern recognition to determine the possible locations of strong earthquakes in the Bulgarian region. The technique assumes the origin of strong earthquakes in morphostructural nodes formed around the intersections of morphostructural lineaments identified by morphostructural zoning. More“Potential Locations of Strong Earthquakes in Bulgaria and the Neighbouring Regions”

Trigger mechanisms of gas hydrate decomposition, methane emissions and glacier breakup in polar regions as the result of deformation tectonic waves

This paper presents a new revolutionary theory of Academician Leopold Isaevich Lobkovsky on the impact of strong subduction earthquakes on the Earth’s climate and the catastrophic collapse of ice shelves as a trigger effect. A seismogenic-trigger mechanism is proposed for the activation of methane emission on the Arctic shelf in the late 1970s, which caused the onset of a sharp climate warming in the Arctic, as well as the intensive collapse of the ice sheet ice shelves of West Antarctica in the late 20th and early 21st centuries, accompanied by the release of methane from the underlying hydrate-bearing sedimentary rocks and the rapid climate warming in Antarctica.

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Productivity within the epidemic-type seismicity model 

The Geophysical Journal International published an article by Doctor of Physical and Mathematical Sciences G. Molchan and his Italian colleagues, devoted to the theoretical analysis of the productivity of seismic events. The productivity of a magnitude m event can be characterized in term of triggered events of magnitude above m – Δ: it is the number of direct ‘descendants’ νΔ and the number of all ‘descendants’ VΔ. There is evidence in favour of the discrete exponential distribution for both νΔ and VΔ with a dominant initial magnitude m (the case of aftershock cluster). We consider the general Epidemic Type Aftershock Sequence model adapted to any distribution of νΔ. Our first result shows that models with branching aftershock structure do not allow for the coincidence of distribution types of νΔ and VΔ (say, the discrete exponential, as in the scientific literature). The second problem is related to the tail behaviour of the VΔ distribution. We show the fundamental difference in tail behaviour of the VΔ – distributions for general-type clusters and clusters with a dominant initial magnitude: the tail is heavy in the former case and light in the latter. The real data demonstrate the possibilities of this kind.

Source: G. Molchan, E. Varini, A. Peresan Productivity within the epidemic-type seismicity model Geophysical Journal International, Volume 231, Issue 3, December 2022, Pages 1545–1557,DOI: 10.1093/gji/ggac269, Published: 22 July 2022

Nonlinear large-scale perturbations of steady thermal convective dynamo regimes in a plane layer of electrically conducting fluid rotating about the vertical axi

In «Mathematics» (Web of Science Q1, Scopus Q2, Impact Factor: 2.592) издательства MDPI published an article «Nonlinear large-scale perturbations of steady thermal convective dynamo regimes in a plane layer of electrically conducting fluid rotating about the vertical axis». This is a joint work of scientists from the IEPT RAS and the University of Porto (Portugalia) Simon Ranjith Jeyabalan, Roman Chertovskih, Silvio Gama и Vladislav Zheligovsky.

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