El 18 de julio 2026 (21horas 24m; hora local), ocurre un sismo de magnitud M5.4 con epicentro a 14 km al S-SO de la ciudad de Chupaca (región Junín), siendo el sacudimiento del suelo percibido en una radio de 150 km. El sismo ocurrió a una profundidad de 9.5 km y está asociado a la reactivación temporal de la falla tectónica Altos del Mantaro ubicada en la Cordillera Occidental, extremo occidental del Valle del Mantaro. La secuencia de réplicas considero la ocurrencia de una réplica de magnitud M5.0 con epicentro a 19 km en dirección SO de la ciudad de Chupaca con foco a una profundidad de 9 km. El sismo y replicas produjeron el sacudimiento del cerro Pucca generando derrumbes de piedras y tierra, así como procesos de licuación de suelos y movimientos de masa en áreas en calles y áreas de pendientes altas. Los valores de aceleración del suelo estimados en el área epicentral fueron en promedio de 75 cm/seg2 , suficiente para producir en respuesta, daños parciales o el colapso de estructuras de adobe propias de la zona. La distribución espacial del daño no obedeció a un patrón de atenuación radial uniforme desde el epicentro. Por el contrario, los daños se presentaron de manera altamente sectorizada y heterogénea, evidenciando una fuerte influencia de las condiciones locales del suelo o efectos de sitio. La distribución de los periodos de respuesta del suelo y su amplificación son coherentes con los daños observados en estructuras de adobe y albañilería en cada distrito evaluado.

Durante el mes de julio de 2026, el Centro Sismológico Nacional (CENSIS) reportó la ocurrencia de 115 sismos con epicentros en el borde occidental y dentro del territorio peruano.

Durante el mes de mayo de 2026, el Centro Sismológico Nacional (CENSIS) reportó la ocurrencia de 83 sismos con epicentros en el borde occidental y dentro del territorio peruano.

Durante el mes de abril de 2026, el Centro Sismológico Nacional (CENSIS) reportó la ocurrencia de 62 sismos con epicentros en el borde occidental y dentro del territorio peruano.

Most of the nitrogen (N) accessible for life is trapped in dinitrogen (N₂), the most stable atmospheric molecule. In order to be metabolized by living organisms, N₂ has to be converted into biologically assimilable forms, so-called fixed N. Nowadays, nearly all the N-fixation is achieved through biological and anthropogenic processes. However, in early prebiotic environments of the Earth, N-fixation must have occurred via natural abiotic processes. One of the most invoked processes is electrical discharges, including from thunderstorms and lightning associated with volcanic eruptions. Despite the frequent occurrence of volcanic lightning during explosive eruptions and convincing laboratory experimentation, no evidence of substantial N-fixation has been found in any geological archive. Here, we report on the discovery of a significant amount of nitrate in volcanic deposits from Neogene caldera-forming eruptions, which are well correlated with the concentrations of species directly emitted by volcanoes (sulfur, chlorine). The multi-isotopic composition (δ¹⁸O, Δ¹⁷O) of the nitrates reveals that they originate from the atmospheric oxidation of nitrogen oxides formed by volcanic lightning. According to these first geological volcanic nitrate archive, we estimate that, on average, about 60 Tg of N can be fixed during a large explosive event. Our findings hint at a unique role potentially played by subaerial explosive eruptions in supplying essential ingredients for the emergence of life on Earth.

Utilizing multistatic specular meteor radar (MSMR) observations, this study delves into global aspects of wind perturbations in the mesosphere and lower thermosphere (MLT) from the unprecedented 2022 eruption of the Hunga Tonga-Hunga Ha'apai (HTHH) submarine volcano. The combination of MSMR observations from different viewing angles over South America and Europe, and the decomposition of the horizontal wind in components along and transversal to the HTHH eruption's epicenter direction allow an unambiguous detection and identification of MLT perturbations related to the eruption. The performance of this decomposition is evaluated using Whole Atmosphere Community Climate Model with thermosphere/ionosphere extension (WACCM-X) simulations of the event. The approach shows that indeed the HTHH eruption signals are clearly identified, and other signals can be easily discarded. The winds in this decomposition display dominant Eastward soliton-like perturbations observed as far as 25,000 km from HTHH, and propagating at 242 m/s. A weaker perturbation observed only over Europe propagates faster (but slower than 300 m/s) in the Westward direction. These results suggest that we might be observing the so-called Pekeris mode, also consistent with the L1 pseudomode, reproduced by WACCM-X simulations at MLT altitudes. They also rule out the previous hypothesis connecting the observations in South America to the Tsunami associated with the eruption because these perturbations are observed over Europe as well. Despite the progress, the L0 pseudomode in the MLT reproduced by WACCM-X remains elusive to observations.

In this study, we investigate the ionospheric disturbances caused by a moderate geomagneticstorm (maximum Kp = 6) occurring between 26th February and 1 March 2023. Ionospheric response for thecoupling between the solar wind, magnetosphere, and ionosphere systems can be observed across variousregions of the globe and it may vary according to the local/regional background ionospheric conditions. Weanalyzed space and ground‐based instruments (e.g., ionosondes, total electron content, GUVI imager,incoherent scatter radar) covering from Antarctica to equatorial latitudes in South America. From a globalperspective, we observed two ionospheric storms. The first, with a negative phase observed as a significantdecrease (>30%) in the F2‐layer critical frequency (foF2), occurred on February 27th at 01:00 UT. This negativephase storm was observed in all the considered regions, with the intensity progressively decreasing from higherto lower latitudes. It is worth mentioning that, for the Antarctic station, we consider the local regime of theWeddell Sea Anomaly. The second ionospheric storm occurred during the recovery phase of the geomagneticstorm on 28th February. In this last case, an enhancement above 30% in foF2 was observed only in the low‐latitude station. Subsequently, the geomagnetic storm produced a super fountain effect at the EquatorialIonization Anomaly resulting in the enhancement of foF2.

Statistical analysis of low latitude spread F is presented for three different longitudinal sectors from Jicamarca (12°S, 76.8°W, −2.5° declination angle) from 2001 to 2016, Ascension Island (7.9°S, 14.4°W, −15.09° declination angle) from 2000 to 2014, Kwajalein (8.71°N, 167.7°E, 7.5° declination angle) from 2004 to 2012. Digisonde data from these stations have been processed and analyzed to study statistical variations of equatorial spread F, a diagnostic of irregular plasma structure in the ionosphere. A new automated method of spread F detection using pattern recognition and edge detection for low latitude regions is used to determine solar and seasonal variation over these three sites. An algorithm has been developed to detect the foF2 and hpF2 parameters and this has been validated by comparisons with manually scaled data as well as with SAMI2 and International Reference Ionosphere models showing good correlation. While significant variation is not observed over the solar cycle, the different longitudes and declination angles contribute to the variations over the seasonal cycle.