Foreshock productivity and rupture nucleation in injection-induced earthquakes in western Canada

August 27, 2026| Source: Science

Foreshock activity is a key consideration in traffic-light protocol (TLP) to mitigate seismic risk from injection-induced earthquakes (IIEs). However, the seismogenic processes of IIE foreshocks remain poorly understood. Using an enhanced western Canada catalog (2014–2024), we analyzed 77 IIE sequences to statistically delineate foreshock patterns before local magnitude ( M L ) ≥ 3 mainshocks. We found that 92% are preceded by foreshocks and that foreshock productivity and spatiotemporal patterns reflect the interplay among fluid injection, the seismogenic index, and the fault stress state. Sequence-specific analyses elucidate three nucleation models: fluid-driven preslip with weakened source asperity, fluid-driven preslip with intact source asperity, and fluid-driven cascade, highlighting the central role of fluids in enabling aseismic slip and interevent stress transfer before mainshock rupture. These results imply that IIE monitoring strategies should be spatially conditioned according to foreshock productivity.

Read the original source →

Multiband condensate of magnons in two dimensions.

Wavelike bosonic particles can accumulate in a single mode characterized by a particular wavelength, and such condensates are at the heart of phenomena such as superconductivity and superfluidity where usually a single complex number describes their state. If there are several flavors of excitations or particles, a vector containing several complex numbers can characterize multicomponent condensation, thus opening new possibilities for textures, dynamics, and devices. Thus far, multicomponent co

Physical/TechSeptember 27, 2026

Indirect reciprocity with dual private assessment.

People often cooperate out of concern for their reputation. The corresponding theory of indirect reciprocity predicts that such cooperation can only evolve if people's opinions of each other are sufficiently correlated. This correlation, however, can be difficult to achieve when individuals form their opinions independently from one another, as in private assessment models. In that case, errors can generate disagreements that propagate throughout a population. Here, we identify a simple mechanis

Physical/TechSeptember 26, 2026

A genetic program for rapid initiation of axillary meristems at the onset of flowering.

Shoot branching patterns and their diversity arise from variable activities of axillary meristems (AMs). A common feature of flowering plants is delayed AM initiation and growth during the vegetative phase, followed by a sudden and rapid acceleration of apical AM initiation during the reproductive phase. The mechanisms underlying this pronounced developmental shift are poorly understood. During tomato floral transition, the primary shoot meristem (PSM) terminates in a flower after producing two

Physical/TechSeptember 26, 2026

David Botstein: A pioneering geneticist and educator 1942-2026.

David Botstein, who died on February 27, 2026, was a towering figure in the field of modern molecular genetics. His research career was largely focused on the development of methods to better understand biological systems, beginning with his early work on Salmonella phage P22 and yeast, where he exploited the use of conditional lethal mutations as suppressors to identify genes with common functions and to order them in a pathway. He is best remembered for developing restriction fragment length p

Physical/TechSeptember 26, 2026

Ultra-narrowband organic room-temperature phosphorescence achieved by boosting low-frequency vibronic coupling.

We pioneered a strategy based on low-frequency vibronic coupling to design narrowband room-temperature phosphorescent (RTP) materials. Here we select coronene derivative (CoDe) system and report that attaching aroyl group to the coronene core disrupts its intrinsic symmetry and introduces abundant low-frequency vibrational modes, thereby affording efficient room-temperature phosphorescence with a full width at half maximum (FWHM) of approximately 25 nm or narrower. In CoDe systems functionalized