Impact cratering record of Fennoscandia

A compilation of circular topographic, morphological, or geophysical structures in Fennoscandia and adjacent areas reveals 62 craterform structures of which 15 appear to be of extraterrestrial origin due to meteorite impact. The majority of the structures are probable and possible impact craters for which there is not yet sufficient proof for impact origin. Four of the proven impact craters contain large volumes of impact melt and many other features of intense shock metamorphism. The age of recognized impact craters vary from prehistoric to late Precambrian. We review the Fennoscandian impact cratering record giving examples of geophysical signatures of impact craters

Geodynamically consistent inferences on the uniform sampling of Earth's paleomagnetic inclinations

Paleomagnetism is a key method to reconstruct the Earth's paleogeography and thus essential for understanding tectonic evolution, but it assumes that the Earth's magnetic field structure has always averaged to a geocentric axial dipole (GAD). The GAD hypothesis may be tested using the observed inclination frequency distribution, but only if continents sampled all of the Earth's latitudes uniformly, which is not known. Here, we provide new insight into the uniform sampling problem by employing a suite of 3D spherical mantle convection models that feature the self-consistent evolution of mantle convection, plate tectonics and continental drift over timescales of 2 Gyr or more. Our results suggest that continents unlikely sampled latitudes uniformly during the Phanerozoic, consistent with previous suggestions. This finding is robust for a variety of geodynamic evolutions with different mantle and lithosphere structures, at least in the absence of true polar wander. For longer sampling durations, uniform sampling typically becomes more feasible, but may only be achieved with confidence after time scales of minimum 1.3 Gyr. This time scale depends on the structure of the mantle and lithosphere and may be shortest when upper mantle viscosity is small such that reduced resistive drag at the cratonic base allows for faster continental drift. Weak plates (low plastic yield strength) promote more dispersed continent configurations, which tends to facilitate uniform sampling. If these conditions are not met, the uniform sampling time scale can easily exceed several billion years. Even the minimum estimate of 1.3 Gyr challenges the validity of using the Phanerozoic inclination frequency distribution to infer the past average magnetic field structure; the approach could however still be applicable using the Precambrian inclination record. (C) 2018 Elsevier B.V. All rights reserved.Peer reviewe

Archaeomagnetic intensity in Finland during the last 6400 years: problems in measurement techniques, dating errors or evidences for a non-dipole field

Archaeomagnetic intensity in Finland has been determined for the past 6400 years with the Thellier technique of bricks, potsherds and baked clays. The normalized intensity shows an increase from -4360 BC to the maximum at AD 500–AD 900, after which it decreases to the present value. The peak at AD 500–AD 900 is not a consequence of the applied Thellier technique since we are able to reproduce the known field values in the laboratory, and some of the bricks yield values which are in broad agreement with the observatory data. We have shown that variations in grain size of the magnetic carriers, cooling rate, fabrik or magnetic refraction are unlikely to cause systematic errors in intensity larger than ten percent. Previously we have demonstrated that the high intensity at AD 500 in Finland can be modelled by a non-dipole field producing enhanced latitude-normalized values at higher latitudes (Finland) and relatively weaker fields at lower latitudes (Bulgaria), and that extrapolation of the present field (IGRF 1990) back in time shows similar behaviour. However, the new Bulgarian smoothed archaeointensity curve by Daly and Le Goff (1996) shows a maximum in Bulgarian curve at ~AD 630 (i.e., 130 years later than in Finland) and another maximum at AD 950 (i.e., 50 years later than in Finland) , and the new relative intensity data of Finnish lake sediments (Saarinen, 1996) reveals a peak at ~AD 870 corresponding roughly with the second maximum. These new curves are somewhat controversial but they east doubt on the previous datings of the Finnish archaeomagnetic materials of the first millennia AD. Here we show that a better match of the Finnish and Bulgarian intensity data with the Finnish lake sediment data can be obtained if the Finnish ages of the first millennium are slightly younger than previously thought. However, the Finnish intensities are still significantly higher than the coeval Bulgarian intensities so that a non-dipole field enhancement may have also been operative

Fennoscandia Paleomagnetics Meeting

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/95029/1/eost8757.pd

Remote Assisted Task Management for ISOBUS Equipped Tractor-Implement Combination

Rosana G. Moreira, Editor-in-Chief; Texas A&M UniversityThis is a paper from International Commission of Agricultural Engineering (CIGR, Commission Internationale du Genie Rural) E-Journal Volume 9 (2007): Remote Assisted Task Management for ISOBUS Equipped Tractor-Implement Combination. Manuscript ATOE 07 011. Vol. IX. July, 2007

Physical properties of 368 meteorites: Implications for meteorite magnetism and planetary geophysics

Petrophysical studies (susceptibility, intensity of natural remanent magnetisation (NRM) and dry bulk density) of 368 meteorites are reviewed together with magnetic hysteresis data for 50 achondrites and chondrites. The relationships between dry bulk density, metallic FeNi-content and porosity will be discussed in the case of L-chondrites. Using the petrophysical classification scheme the meteorite class and the petrologic group of a sample can be determined in most of the cases providing a rapid means for determining a preliminary classification of a new sample. In addition, the petrophysical database provides a direct source of basic physical properties of the small bodies in the solar system. Paleointensity determinations with Thellier technique will be presented for 16 meteorites representing different chondrite groups. The results yield high paleofield values ranging from 51μT to 728μT for the magnetically hardest meteorites consistent with previous studies. However, these values must be looked with caution, because of possible physico-chemical or mineralogical alterations during heating

Rock Magnetic Studies of the Neuschwanstein EL6 Chondrite : Implications on the Origin of its Natural Remanent Magnetization

Peer reviewe

Palaeomagnetism of Middle Ordovician Carbonate Sequence, Vaivara Sinimaed Area, Northeast Estonia, Baltica

The hill range of Vaivara Sinimaed in northeast Estonia consists of several narrow east-to northeast-trending glaciotectonic fold structures. The folds include tilted (dips 4-75 degrees) Middle Ordovician (early Darriwilian) layered carbonate strata that were studied by mineralogical, palaeomagnetic, and rock magnetic methods in order to specify the post-sedimentational history of the area and to obtain a better control over the palaeogeographic position of Baltica during the Ordovician. Mineralogical studies revealed that (titano) magnetite, hematite, and goethite are carriers of magnetization. Based on data from 5 sites that positively passed a DC tilt test, a south-easterly downward directed component A (D-ref = 154.6 degrees +/- 15.3 degrees, I-ref = 60.9 degrees +/- 9.7 degrees) was identified. The component is carried by (titano) magnetite, dates to the Middle Ordovician (Plat = 17.9 degrees, Plon = 47.3 degrees, K = 46.7, A95 = 11.3 degrees), and places Baltica at mid-southerly latitudes. Observations suggest that in sites that do not pass the tilt test, the glaciotectonic event has caused some rotation of blocks around their vertical axis.Peer reviewe

Effectiveness Evaluation on Entrepreneurship Education

In EU there are hundreds and thousands ESF funded projects and several studies of these projects effectiveness have been done, but how many of these studies are focused on changes in entrepreneurship education specially in teachers thinking and action and changes on the organizational level? Note so many. That’s why I try to discover answers to the question: Is it possible and how it is possible to evaluate the Entrepreneurship Education project or program especially when taking teachers changes in thinking and action and changes on the organizational level. In the AUSESBC (Aalto University School of Economics Small Business Center) there is the effectiveness evaluation project, funded by ESF, whom called “Entrepreneurship Education joint and evaluation “YKOONTI. Project has been carried out 1.9.2010 – 30.04.2012 in Finland. The main idea of the project “YKOONTI” is to collect data and evaluate the Entrepreneurship Education ESF funded project’s which have been taken during 2000 – 2010. In this paper there were described some detail of the frame effectiveness evaluation and described one project which was evaluated during the project “YKOONTI”. The project evaluated in this paper was “FIRMA” which was carried in South Finland in the Vocational College “ESEDU”. Researcher has been decided to use in evaluation the frame of Kirkpatricks (1959, 2006) effectiveness evaluation four level model. Model is well known when evaluated effectiveness in management program but not so known when evaluating entrepreneurship education program or project. When thinking why evaluation is important is has been said, “Evaluation is about revealing the value of a project” (ETUI‐REHS Project monitoring and evaluation – guidelines). The EU has been said “The purpose of evaluation is to examine how well a project answers to the need it is done for, that is to evaluate the results and effects of the project. The method of implementation of the evaluation depends, among other things, on the stage it is done in and on who does it. The function of evaluation is also to yield information for the planning of the project, to help in the effective division of resources and to improve the quality of the project.” (European Commission 2004, 9.