A 200 km suspected impact crater Kotuykanskaya near Popigai, Siberia, in the light of new gravity aspects from EIGEN 6C4, and other data

We provide arguments in favour of impact origin of a 200 km suspected impact crater Kotuykanskaya near Popigai, Siberia, Russia. We use the gravity aspects (gravity disturbances, the Marussi tensor of the second derivatives of the disturbing geopotential, the gravity invariants and their specific ratio, the strike angles and the virtual deformations), all derived from the combined static gravity field model EIGEN 6C4, with the ground resolution of about 10 km and a precision of about 10 milliGals. We also use the magnetic anomalies from the model EMAG2 and emphasize the evidence of much deeper sources in the suspected area, constraining the impact origin of this structure.Web of Science101art. no. 609

Global and regional seasonal variations of the geoid detected by grace

Since 2002, the US-German GRACE (Gravity Recovery and Climate Experiment) mission has been providing a precise survey of the Earth's time-variable gravity field, with unprecedented temporal and spatial sampling. GRACE time-variable gravity fields provide a means of measuring the temporal and spatial variations of mass redistribution within the Earth system. The GRACE mission has started a new era in studying a series of geophysical problems ranging from deep Earth structure to tracking mass redistribution on and near the surface of the Earth. Time variability of the gravity field presented here is based on the transformation of “monthly gravity field models” to the geoid. We show the changes caused by the global water cycle and land hydrology.Web of Science10329128

Hypotheses about geoglyphs at Nasca, Peru: new discoveries

The known hypotheses about the reasons why the geoglyphs in the Nasca and Palpa region of Peru were created are many: roads/paths, rituals/ceremonials, use of hallucinogens, astronomical meaning, influence of extraterrestrials, underground water… and so on. We present a new hypothesis, formulated by J. Sonnek (first published in 2011) in the context of all previous hypotheses.1 Sonnek explains the geoglyphs as tidied work areas for the production of rope and nets, although he goes much further than Stierlin. This eccentric hypothesis now has not only experimental but also archaeological and ethnographical support, which is presented here. Geoglyphs of a special shape were discovered in the pampas; they may represent technical objects – different types of ‘rope twisters’. Following this idea, Sonnek made technical devices (using today’s materials) and tested them in practice; they work perfectly, see his YouTube videos.2 In November 2012, wooden pieces, which may be the remnants of ropemaking, were collected from the pampa near the towns of Nasca and Palpa, in vicinity of these hypothetic ropemaking places. Radiocarbon testing by 14C standardized radio-carbon age according to Stuiver-Polach convention and Accelerator Mass Spectroscopy (AMS) of these wood pieces shows the age to be in a wide range from Early Nasca to the 17th century (and to our epoch with a fake geoglyph, too), thus supporting (but surely not proving) the new hypothesis. Moreover, in the Quechua language, the word huasca, waskha (read: uasca) means a rope or cord or place where these are produced. This word is very similar to ‘nasca’

Využití rezonancí drah umělých družic k popisu gravitačního pole Země

12112

Geostacionární družice v dynamické družicové geodézii

24825

Odhady přesnosti modelů tíhového pole pomocí nezávislé družicové diferenciální altimetrie

A continuous progress in the Earth gravity field modeling requires some refinements in their accuracy assessments. The method based on latitude lumped coefficients, which makes use of satellite crossover altimetry data (independent of the tested gravity models) has been developed in years 1992 - 2000. It was applied on various gravity models, recently on EIGEN IS, which already includes data from the CHAMP mission. For the first time, EIGEN IS model has degree-dependent calibration factors and we tested and confirm that their choice is a right one

Přínos družicové altimetrie k určení tvaru a gravitačního pole Země

19319

Metoda kolokací a dráhové rezonance umělých družic Země

31732