Months-long seismicity transients preceding the 2023 MW 7.8 Kahramanmaras earthquake, Türkiye.

Short term prediction of earthquake magnitude, time, and location is currently not possible. In some cases, however, documented observations have been retrospectively considered as precursory. Here we present seismicity transients starting approx. 8 months before the 2023 MW 7.8 Kahramanmaras earthquake on the East Anatolian Fault Zone. Seismicity is composed of isolated spatio-temporal clusters within 65 km of future epicentre, displaying non-Poissonian inter-event time statistics, magnitude correlations and low Gutenberg-Richter b-values. Local comparable seismic transients have not been observed, at least since 2014. Close to epicentre and during the weeks prior to its rupture, only scarce seismic activity was observed. The trends of seismic preparatory attributes for this earthquake follow those previously documented in both laboratory stick-slip tests and numerical models of heterogeneous earthquake rupture affecting multiple fault segments. More comprehensive earthquake monitoring together with long-term seismic records may facilitate recognizing earthquake preparation processes from other regional deformation transients.

Spatial and temporal multiplet analysis for identification of dominant fluid migration path at The Geysers geothermal field, California.

Multiplet analysis is based on the identification of seismic events with very similar waveforms which are used then to enhance seismological analysis e.g. by precise relocation of sources. In underground fluid injection conditions, it is a tool frequently used for imaging of subsurface fracture system. We identify over 150 repeatedly activated seismic sources within seismicity cluster induced by fluid injection in NW part of The Geysers geothermal field (California). Majority of multiple events (ME) occur along N-S oriented planar structure which we interpret as a fault plane. Remaining ME are distributed along structures interpreted as fractures, forming together a system of interconnected cracks enabling fluid migration. Temporal analysis reveals that during periods of relatively low fluid injection the proportion of ME to non-multiple events is higher than during periods of high injection. Moreover, ME which occur within the fault differ in activity rate and source properties from ME designating the fractures and non-multiple events. In this study we utilize observed differences between ME occurring within various structures and non-multiple events to describe hydraulic conditions within the reservoir. We show that spatial and temporal analysis of multiplets can be used for identification and characterization of dominant fluid migration paths.

[Perioperative preventive use of ciprofloxacin in patients with cancer of the larynx]. / Profilaktyka okolooperacyjna z zastosowaniem ciprofloksacyny u chorych na raka krtani.

In comparative study of patients with laryngeal cancer, perioperative prophylaxis with ciprofloxacin was estimated. The drug was administered intravenously 200 mg twice daily, for five days to groups of 95 patients. Bacteriological examinations performed intraoperatively mostly revealed Gram-positive germs. The intravenous form of ciprofloxacin was very effective, resulting in complete healing of the operative wound in shorter time than in control groups. The drug has been well tolerated and no side effects were observed.