Since its last eruption from 1990-1995, Unzen Volcano (Shimabara Peninsula, Japan) has been quiescent since. At its summit a complex Dacitic dome that expanded towards the East, in the direction of the Mizunashigawa-valley has grown during the eruption onto previously deposited volcanoclastic sediments. As a small portion of the domes have generated rockfalls and as the surrounding gullies have been eroding headwards, the stability of the dome and its evolution is essential for hazards and disaster-risk monitoring and for understanding the decadal-scale volcanic geomorphological change occurring in between eruptions. Therefore, the present contribution aims to (1) quantify the dome movement and (2) separate the different parts of the dome to understand how it deforms; and (3) what is the link between rainfalls and the dome movement. The method relies on the Unzen GbSar system (Ground Based radar interferometry system) and on hourly rainfalls from raingage stations at Unzen Volcano. As a result, the authors have identified that (1) the lower part of the dome rises and falls more rapidly than the upper part of the dome when rainfall is less than 100 mm/48 hours, and (2) the upper and lower parts of the dome move up and down at the same level when rainfall exceeds 100 mm/48 hours. In turn, when rainfall exceeds 250 mm/48 hours, then the upper part of the dome also displays further downward movement, so that the entire dome might be moving down like an accordion.
The geomorphological characteristics of the loess succession at Malá nad Hronom (Slovakia) mean that it provides a valuable opportunity for the investigation of differences in soil formation in various topographic positions. Along with the semiquantitative characterization of the paleosols (on the basis of physical properties, texture, the characteristics of peds, clay films, horizon boundaries), high-resolution field magnetic susceptibility measurements and sampling were carried out along four different sections of the profile. Samples for luminescence dating were also taken, in order to establish the chronostratigraphical position of the paleosols studied. The comparison of various proxies revealed the differences in soil formation in a dynamic aggradational microenvironment for the same paleosol horizons located in various positions along the slope. Contrary to expectation, paleosols developed in local top or slope topographical positions did not display significant differences in e.g. in their degree of development, nor the characteristics of their magnetic susceptibility curves. In the case of paleosols in positions lower down the slope, signs of quasi-permanent sediment input could be recognized as being present as early as during the formation of the soil itself. This sediment input would seem to be surpassed in the case of pedogenesis strengthened by the climate of the last interglacial (marine isotope stage - MIS 5). Pedogenesis seems to be sustained by renewed intense dust accumulation in the Late Pleistocene, in MIS 3, though compared to MIS 5, the climate of MIS 3 did not favor intense pedogenesis. Despite the general belief that loess series formed in plateau positions can preserve terrestrial records without significant erosion, in the case of the Malá nad Hronom loess this is not so. Compared to the sequence affected by erosional events in the local top position, the sequence affected by quasi-continuous sediment input in the lower slope position seems to have preserved the soil horizons intact.
Abstract Finding planetary bodies in the Solar system and beyond, with surface or subsurface oceans, which may harbor life, is one of the main goals of planetary studies. As a result of this search, an exponentially growing number of exoplanets have been discovered lately, which provides us with a unique opportunity to build and test new theories. Here, we introduce the Extraterrestrial Oceanography (ExTerrO) framework, and its focuses, such as the evaluation of the parameters, found in the exoplanet dataset(s), from a comparative astrogeological point of view, including, i) the influence of those parameters in surface ocean formation, and ii) their possible role as surface ocean proxy, standing individually or as a part of a more complex index. The theory behind the research considers that the more of the parameters applicable to an exoplanet with some divergence from known and well-examined “pilot planetary bodies” with surface oceans, the greater the possibility of surface ocean formation. Based on the preliminary results of the framework, orbital parameters, such as eccentricity and semi-major axis, and the planetary mass affect ocean formation-related processes the most and are potential candidates as future ocean formation probability proxies individually and/or as a part of more complex indices.
This document contains Supporting Data for the manuscript "Potential drivers of disparity in early Middle Pleistocene interglacial climate response over Eurasia" by B. Bradák, G. Újvári, T. Stevens, M.F. Bógalo, M. I. González, and M. Hyodo, submitted to Paleoceanography and Paleoclimatology. Content description: AMS_raw [Sheet 1]: the sheet contains the raw AMS (anisotropy of magnetic susceptibility) data which was used during the determination of paleowind directions. AMS_stereoplots [Sheet 2]: the sheet contains the reconstructed paleowind direction is based on the stereoplot analysis and the alignment of the kmax axis. IRM_unmix_GAPplots [Sheet 3]: the sheet contains the so called gradient acquisition plots, used during the decomposition of isothermal remanent magnetization (IRM) curves and indicating the separated populations of magnetic components. IRM_unmix_raw [Sheet 4]: the sheet contains the characteristics of the magnetic components, identified during the decomposition of IRM curves. Xlf_fd_raw [Sheet 5]: the sheet contains all of the measured magnetic susceptibility frequency dependent magnetic susceptibility data from the profile and its average unit by unit. Xbckg [Sheet 6]: the sheet contains the Xlf vs. Xfd plot which is essential to the determination of background susceptibility (Xbckg) and the paleoprecipitation data. Data (Fig.2) [Sheet 7]: the complex dataset contains essential information about the units of the profile and about the proxy data, which were used during the analysis and appears at Fig. 2. As an additional information it contains step by step information about the calculation of paleoprecipitation values and about the calculation of IRM proxies. Age-depth model (Fig. 3) [Sheet 8]: the sheet contains data and additional information about the age model, used in the study and appears at Fig. 3. Pleist wind in Eurasia (Fig. 4) [Sheet 9]: the sheet summerizes basic information about the profiles which was used during the determination of the influence of various climate centres and characteristic wind directions. Data (Discussion) [Sheet 10]: The sheet summarises the information about the paleoenvironment reconstructed between MIS19 and MIS11 at Paks succession.
The morphostratigraphical subdivision of the Danube terrace system of the Visegrad Gorge was presented by PECSI (1959). However, in recent decades new studies have revealed some problems with this earlier model. The appearance of the gravel sediments in the high level terraces (V–VIII) is not continuous, and thus the morphostratigraphical position of the terrace level cannot be followed clearly. Consequently, for the correlation of the terrace levels a detailed analysis of the overlaying bed of the gravel horizon is necessary in order to reach more convencing conclusions. A litho stratigraphical description of the overlying sequences and the identification of the lithologically unique, or rare gravel components of the marker sediments, could provide more accurate information about the separation and correlation of the different terrace levels. During the investigation which is the subject of this paper, an interpretation of the geomorphological features of the area using field and digital elevation methods was carried out. Furthermore, the stratigraphic description of overlaying sediments and the fine-grained pebble examination (FPE) method were applied to get more information about the morphostratigraphical position of the high level terrace systems.
Abstract Terrestrial records of the last geomagnetic reversal often have few age constraints. Chronostratigraphy using suborbital-scale paleoceanic events during marine isotope stage 19 may contribute to solving this problem. We applied the method to an 8 m long, high-resolution paleomagnetic record from a loess sequence in China and revealed millennial-to-sub-centennial scale features of the Matuyama–Brunhes (MB) transition. All samples were subjected to progressive thermal demagnetization with 14–15 steps up to 650–680 °C. As a result, 96% of the samples yielded a high-quality remanent magnetization. The MB transition terminated with a 75 cm thick zone with nine polarity flips. The polarity flip zone, dated at about 779–777 ka, began between the warm events “I” and “J” and terminated at the end of the cooling event coincident with the lowest axial-dipole strength interval. Most polarity flips occurred within 70 years. The virtual geomagnetic poles (VGPs) in the upper polarity flip zone clustered in the SW Pacific region, where the MB transitional VGPs from lavas of the Hawaiian and Canary Islands and lacustrine deposits of Java also clustered. These sites were probably dominated by dipolar fields. The absence of transitional fields across polarity flips implies a short time span for averaging fields due to a thin loess-magnetization lock-in zone. The reverse-to-normal polarity reversal dated at about 778 ka in Lingtai occurred at the end of the SW Pacific VGP zone, an important key bed for MB transition stratigraphy. The reversal is a good candidate for the main MB boundary. We found an excursion at about 766 ka spanning about 1 ka.
A Middle Miocene, ~8 m thick pyroclastic succession, reported from the Bükk Foreland Volcanic Area (BFVA) in Northern Hungary (Central Europe) specified here as the Jató Member, was produced by silicic phreatomagmatism (Phreatoplinian sensu lato). Two well-preserved outcrops ~8 km apart and inferred to be within ~10–50 km from source represent the discontinuously exposed, layered, paleosol-bounded, phreatomagmatic Jató Member. They show an identical phenocrystal assemblage of feldspar, biotite and amphibole without weathered zones or signs of erosion, that suggest deposition in one eruption phase lasting hours to months. The succession contains three subunits: 1) subunit A, 1.8 m thick, a series of well-sorted fine to coarse ash or lapilli tuff layers with constant thickness; 2) subunit B, 2.1 m thick, a series of normal-graded layers with an upper fine-grained zone containing abundant ash aggregates with a coarser-grained core and distinctively finer-grained outer rim; 3) subunit C, 4.5 m thick, a massive, poorly to well-sorted coarse ash with gas escape structures and ash aggregates at its base. The upward change of these lithofacies implies an initially sustained dry fallout-dominated deposition of ash and pumice lapilli resulting in subunit A. Subsequently, multiple wet and dilute Pyroclastic Density Currents (PDCs) dispersed subunits B and C. The general abundance of PDC-related ash aggregates in the middle-upper part of the succession (particularly in subunit B), and the transformation of a fall-dominated to a collapsing depositional regime producing wet dilute PDCs, imply the increasing influence of water during the eruption (Phreatoplinian sensu lato). The presence of water is related to an epicontinental sea during Middle to Late Miocene in the Carpatho-Pannonian region. The transition from an initial dry magmatic phase generated fallout activity followed by the emplacement of wet PDCs' rich in ash aggregates, when external water infiltrated from a surrounding lake or sea water entered the vent.
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