Maximum Vertical Rate Research Articles

Glacis geometry as a geomorphic marker of recent tectonics: The Guadix–Baza basin (South Spain)

The Guadix–Baza basin occupies 4000 km 2, and constitutes the largest intramontane basin of the Betic Cordillera (Southern Spain). It has a well preserved geomorphic surface, a glacis, which started to be eroded when the basin conditions changed from endorheic to exorheic. Taking into account its large preserved surface area (more than 1200 km 2) and its pre-deformational geometry, this geomorphic surface is a useful marker of recent deformation. Combining geological and geomorphological data and high resolution DEM, topographic profiles of the glacis have been produced to estimate vertical displacements caused by active compression and extension structures. These structures have produced relative vertical displacements of up to 100 m from the late middle Pleistocene to the present. Assuming an age for the glacis of between 205 and 600 ka, it has been possible to estimate long-term minimum and maximum vertical rates of the activity of normal faults and folds using this geomorphic surface as a marker. Vertical slip rates range from 0.07 to 0.49 mm/year for the main active normal faults and vertical folding rates range from 0.05 to 0.17 mm/year for several active folds. These long-term vertical slip and folding rates are in accordance with other values previously estimated in other sectors of the Betic Cordillera. When present, detailed geomorphic study of recent glacis is an excellent tool for evaluating active tectonics over large regions.

The carbonate tectonic units of northern Calabria (Italy): a record of Apulian palaeomargin evolution and Miocene convergence, continental crust subduction, and exhumation of HP–LT rocks

In northern Calabria (Italy), the metasedimentary succession of the Lungro–Verbicaro tectonic unit preserves mineral assemblages suggesting underthrusting to depths in excess of 40 km. Internal deformation of these rocks occurred continuously during the following decompression. Index mineral composition associated with progressively younger tectonic fabrics indicates that a substantial part of the structural evolution took place within the blueschist-facies P – T field. Despite their tectonic and metamorphic history, the rocks of the Lungro–Verbicaro Unit preserve significant sedimentary and palaeontological features allowing correlations with successions included in adjacent thrust sheets and the reconstruction of the Mesozoic continental margin architecture. The subduction–exhumation cycle recorded by the Lungro–Verbicaro Unit is entirely of Miocene age. This portion of the Apulia continental palaeomargin was involved in convergence-related deformation not earlier than the Aquitanian. The integration of our results with available constraints on the tectonic evolution of the Apennine–Calabrian Arc system suggests that subduction and most of the subsequent exhumation of the Lungro–Verbicaro Unit occurred, up to Langhian time, at maximum vertical rates in excess of 15 mm a −1 . The exhumation process was then completed, at much slower rates (<2 mm a −1 ) in Late Miocene time, as indicated by both apatite fission-track data and stratigraphic information.

TCAS-II를 응용한 무인항공기의 충돌회피기동 연구

본 논문에서는 항공기충돌방지장치인 TCAS-II를 응용한 무인항공기의 충돌회피를 다룬다. TCAS-II의 최소운용성능표준 문서에 기초한 시뮬레이션 프로그램을 구현하고, TCAS-II가 제공하는 다양한 수직회피 명령을 자동조종장치의 입력으로 변환하여 최대고도변화율이 상이한 두 가지 무인항공기의 충돌회피 성능을 비교분석한다. 낮은 최대고도변화율을 가진 무인항공기에 TCAS-II를 적용할 때 발생 가능한 Near Mid-Air Collision을 방지할 수 있는 방안으로서, 최대고도변화율과 고도를 고려한 개선된 알고리듬을 제안하였다. 이 알고리듬은 ADS-B 개념에 의한 보다 넓은 감시범위가 제공된다는 전제하에 사용될 수 있다. In this paper, the collision avoidance of Unmanned Aerial Vehicles(UAVs) by applying the Traffic alert and Collision Avoidance System II(TCAS-II) is introduced. The performances of two UAVs whose maximum vertical rates are different each other are compared and analysed by not only converting many TCAS-II commands into an autopilot input but also implementing a computer program based on the Minimum Operational Performance Standards for TCAS-II. As the alternative to a possible Near Mid-Air Collision for UAVs whose maximum vertical rates are low, we have proposed a modified algorithm considering the maximum vertical rate and altitude. The modified algorithm is available on the assumption that a wider surveillance range is provided by a ADS-B system.

Geodetic constraints on glacial isostatic adjustment in Europe

Direct measurements of surface deformation due to Glacial Isostatic Adjustment (GIA) in Europe have been so far mostly limited to the present‐day uplift area. Here, we use permanent GPS networks results to investigate the significance of GIA effects in Europe south of Fennoscandia. We show that uplift in Fennoscandia is surrounded by subsidence reaching as far south as the Alps, with a maximum vertical rate of 1.5 mm/yr between 50.5–53°N. Horizontal velocity gradients show shortening between Fennoscandia and north‐central Europe with strain rates of ∼10−9 yr−1 and principal compressional strain axis pointing to the Gulf of Bothnia in a radial pattern. We find a very good quantitative agreement with the 3D surface displacement predicted by Milne et al. (2001), although the increase of misfit in far‐field of Fennoscandia suggests that geodetic data outside of the uplift area may bring additional constraints to the rheological parameters used in GIA models.

Simulated effects of racetrack material properties on the vertical loading of the equine forelimb

One of the factors cited as contributing to racing injuries of horses is the condition of the racetrack surface. This study examines the possible effects of different dirt racetrack surfaces by using dynamic modelling of the horse and track to quantify the vertical loading of the hoof and coffin joint. Results indicate that as the stiffness of the racetrack material increased from a weak soil to a rock surface (constant soil damping ratio of 15% of critical damping), the maximum track deflection decreased from 5.1 to 1.2 cm; stance phase duration decreased by 60%; energy dissipation decreased by 72%; maximum vertical ground reaction force and coffin joint force increased by 19% and maximum vertical rate of loading increased by 219%. Varying the soil damping ratio from 5 to 30% of critical damping had only small effects on the loading response, changing the above parameters by less than 5% for the medium soil type simulated. These results indicate that the track surface may have a profound effect on the loading conditions of the horse’s limb, with the surface stiffness properties having a greater effect on loading than the surface damping properties. Design of appropriate race track surfaces may therefore be more dependent on selection of soil for structure, rather than soil amendments which have been used primarily to alter damping characteristics.