Los altos porcentajes de concentración de precipitación diaria en pocos días, pueden incrementar el potencial de erosión, inestabilidad de laderas y riesgo de inundaciones, siendo estos problemas comunes en el Perú, por lo que es importante el conocimiento acerca de la precipitación a nivel diario. En este articulo, se ha llevado a cabo una investigación acerca de los patrones espaciales y temporales de la concentración de precipitación diaria en los andes centrales del Perú, mediante el índice de concentración (IC), que evalúa la variación de la valoración de precipitación diaria, la contribución de grandes lluvias a la cantidad total presentada. El índice es aplicado a una curva exponencial como Y = aX exp(bX ) , el cual ajusta el porcentaje acumulado de precipitación en Y contribuida por el porcentaje acumulado de días X llevado a cabo en un lugar, en el periodo 19...

The 1994 Bolivia earthquake, with hypocenter at 641 km depth, is the greater magnitude earthquake recorded instrumentally in the last 50 years. This earthquake did not produce damage in the surface but was perceived in most of the southern hemisphere. This seismic event had a multiple (complex) rupture process during 55 s and the rupture propagated towards N-E direction with a 1.6 km/s mean velocity. The size of the rupture was around 90 km; however, the principal asperity was contained within an area of 40×40 km2. The rupture corresponds to a focal mechanism of normal type with planes oriented in the E-W direction, being the fault plane close to the vertical. The scalar seismic moment calculated by teleseismic body waveform inversion is 2.30 × 1021 Nm and corresponds to a magnitude of Mw 8.2.

El terremoto de Bolivia de 1994, con hipocentro a 641 km de profundidad, es el de mayor magnitud registrado instrumentalmente en los últimos 50 años. No produjo daños en la superficie pero fue percibido en la mayor parte del hemisferio sur. Este evento sísmico tuvo un proceso de ruptura múltiple y complejo durante 55 s y la ruptura se propagó en la dirección N-E con una velocidad promedio de 1.6 km/s. La longitud de la ruptura fue de 90 km y la aspereza principal estuvo contenida en un área de 40×40 km2. La ruptura corresponde a un mecanismo focal de tipo normal con planos orientados en dirección E-O, siendo el plano de ruptura cercano a la vertical. El momento sísmico escalar calculado mediante inversión de ondas de volumen es 2.30 × 1021 Nm y corresponde a una magnitud de 8.2 Mw.

The Earth is a dynamic system and as such is susceptible to the action of seismic and geological events. For many problems in science and engineering there is a need to establish a three-dimensional coordinate system for geodesic measurements. With the advancement of satellite geodesy, is currently possible to determine the horizontal coordinates of a point on the Earth’s surface with errors less than one centimeter. The problem arises when trying to obtain the vertical coordinate, since satellites provide heights with reference to an ellipsoid, which is not an equipotential surface. For obtaining the vertical coordinate, the reference surface of the geoid or mean level sea is taken. In the present study, a methodology to determine the mean sea level in the Paracas Bay is provided, using an ultrasonic level sensor interfaced to a computer. The data are digitally processed using filteri...

Due to its complex topography, the Lake Titicaca region, located in the southern tropical Andes, presents great challenges for atmospheric modeling. This study aims to improve the representation of precipitation and air surface temperature using the Weather Research and Forecasting (WRF) model at high spatial resolution (2 km), during the austral summer of 2020. We conducted 11 experiments with different configurations of topography, land use, physical parameterizations, and lake surface temperature (LST). Each experiment was evaluated considering in-situ data from the Peruvian-Bolivian region and gridded precipitation products. For precipitation, the best configuration, with an average bias close to zero mm, includes using the GMTED2010 topography (not smoothed) and the land use data of Eva et al. (2004), along with the Purdue Lin microphysics and the Grell 3D cumulus scheme. For air te...

The first weather radar campaign over Lima, the capital of Peru, a desertic area on the western side of the Peruvian Andes, was carried out to study the occurrence of rain events in summer 2018. The weather radar was installed strategically and was able to overlook three river basins: Rimac, Chillón, and Lurin. An X-band radar (PX-1000) was used, which operates at 9.55 GHz. PX-1000 was built by the Advanced Radar Research Center (ARRC) at the University of Oklahoma (U.S.A.). The radar operated from January 26th to April 1st, 2018, at Cerro Suche located 2910 m ASL and 55 km from the city of Lima. The PX-1000 performed plan-position-indicators (PPI) for elevations starting at 0° up to 20°. The data presented here were obtained using a three-dimensional constant-altitude plan-position-indicator (3D CAPPI), which was generated by high resolution (250 m) nearest point algorithm. © 2021

A set of instruments to measure several physical, microphysical, and radiative properties of the atmosphere and clouds are essential to identify, understand and, subsequently, forecast and prevent the effects of extreme meteorological events, such as severe rainfall, hailstorms, frost events and high pollution events, that can occur with some regularity in the central Andes of Peru. However, like many other Latin American countries, Peru lacks an adequate network of meteorological stations to identify and analyze extreme meteorological events. To partially remedy this deficiency, the Geophysical Institute of Peru has installed a set of specialized sensors (LAMAR) on the Huancayo observatory (12.04◦ S, 75.32◦ W, 3350 m ASL), located in the Mantaro river basin, which is a part of the central Andes of Peru, especially in agricultural areas. LAMAR consists of a set of sensors that are us...