Suchergebnisse

Horizontal-to-Vertical Spectral Ratios (HVSR) and Rayleigh group velocity dispersion curves (DC) can be used to estimate the shallow S-wave velocity (VS) structure. Knowing the VS structure is important for geophysical data interpretation either in order to better constrain data inversions for P-wave velocity (VP) structures such as travel time tomography or full waveform inversions or to directly study the VS structure for geo-engineering purposes (e.g., ground motion prediction). The joint inversion of HVSR and dispersion data for 1D VS structure allows characterising the uppermost crust and near surface, where the HVSR data (0.03 to 10s) are most sensitive while the dispersion data (1 to 30s) constrain the deeper model which would, otherwise, add complexity to the HVSR data inversion and adversely affect its convergence. During a large-scale experiment, 197 three-component short-period stations, 41 broad band instruments and 190 geophones were continuously operated for 6 months (April to October 2017) covering an area of approximately 1500km2 with a site spacing of approximately 1 to 3km. Joint inversion of HVSR and DC allowed estimating VS and, to some extent density, down to depths of around 1000m. Broadband and short period instruments performed statistically better than geophone nodes due to the latter's gap in sensitivity between HVSR and DC. It may be possible to use HVSR data in a joint inversion with DC, increasing resolution for the shallower layers and/or alleviating the absence of short period DC data, which may be harder to obtain. By including HVSR to DC inversions, confidence improvements of two to three times for layers above 300m were achieved. Furthermore, HVSR/DC joint inversion may be useful to generate initial models for 3D tomographic inversions in large scale deployments. Lastly, the joint inversion of HVSR and DC data can be sensitive to density but this sensitivity is situational and depends strongly on the other inversion parameters, namely VS and VP. Density estimates from a HVSR/DC joint inversion should be treated with care, while some subsurface structures may be sensitive, others are clearly not. Inclusion of gravity inversion to HVSR/DC joint inversion may be possible and prove useful ; This work was funded by TOTAL under the framework of the Orogen project, with funding from the Spanish government through the 'Severo Ochoa Centre of Excellence' accreditation (CEX2019-000928-S) and the research team RNM-194 of Junta de Andalucía (Spain). ; Peer reviewed

The way of life of the outstanding Russian geographer, traveler, humanist, one of the initiators of creation and the founders of the Russian Imperial geographical society, honorary member of the St. Petersburg Mineralogical Society and one of the first successful climbers in the world Platon Aleksandrovich Chikhachev was bright, full of discoveries, adventures, tragic episodes, public recognition and oblivion. He was born in 1812, was on military service from 1828 to 1831, traveled to North and South America in 1835–1837, and in 1840– 1845 to Europe and Russia, where he took part in the creation of the Imperial geographical society. At the very beginning of his life, being a 16-years-old officer, he participated in 3 wars, later in the famous Khiva campaign of 1839–1840, and in the Crimean war in 1855. In 1856, he married and went to Europe. He died in Versailles in 1892, and was buried in Nice at the Russian cemetery. After retiring from the army in 1833, he devoted himself to travelling to Europe and the New World. He became the first Russian who in the early 19th century crossed Mexico from the East to the western coast of the Pacific Ocean; made a dangerous crossing on horseback in South America – from Chile through the Andes and pampas of Argentina reached Buenos Aires. Platon Chikhachev first conquered the mountain peaks – Pichincha volcano in Ecuador and Aneto peak, the highest point of the Pyrenees, and became one of the first climbers in Europe. The article adds new data to the well-known features of the biography of a guard officer, scientist, and traveler: little-known episodes of life, including those related to his stay in the homeland; it is clarified the sequence of events and the chronicle of the life of a scientist and traveler based on primary sources. The facts of Platon Chikhachev's routes were specified, and contribution to the development of national and world geography was assessed. ; Жизненный путь выдающегося русского географа, путешественника, гуманиста, одного из учредителей Русского императорского географического общества, почетного члена Санкт-Петербургского Минералогического Общества и одного из первых успешных альпинистов в мире Платона Александровича Чихачева был ярок, полон открытий, приключений, трагических эпизодов, общественного признания и забвения. Он родился в 1812 г., путешествия по Северной и Южной Америке провел в 1835–1837 гг.; в 1839–1840 гг. участвовал в Хивинском походе; в 1840–1845 гг. – путешествовал по Европе и России, совершил восхождение в Пиренеях на пик Ането. В 1855 г. участвовал в Крымской войне, а в 1856 г. – женился и уехал в Европу. Умер в Версале в 1892 г., похоронен в Ницце на Русском кладбище. В самом начале жизненного пути, будучи 16-летним офицером, участвовал в трех войнах, в знаменитом Хивинском походе 1839–1840 гг., а позднее – в Крымской войне. После отставки из армии в 1833 г. посвятил себя путешествиям по Европе и Новому Свету. Он стал первым из русских, кто в начале XIX в. пересек Мексику с востока до западного побережья Тихого океана; совершил опаснейший переход на лошадях по Южной Америке – из Чили через Анды и пампасы Аргентины достигнул Буэнос-Айреса. Пл. Чихачев впервые покорил горные вершины – вулкан Пичинча в Эквадоре, пик Ането – высшую точку Пиренеев и стал одним из первых альпинистов Европы. В статье к известным штрихам биографии гвардейского офицера, ученого, путешественника добавлены новые данные: малоизвестные эпизоды жизни, в том числе связанные с пребыванием его на родине; внесена ясность в последовательность событий и в хронику жизни ученого и путешественника на основе первоисточников; уточнены факты маршрутов Платона Чихачева и вклад в развитие отечественной и мировой географии.