Do Shapes of Elevational Gradients of Species Richness Depend on the Vertical Range Studied? The Case of the Himalayas

We retrieved shapes of elevational species richness gradients (unimodal, decreasing, increasing) from 64 publications, studying Himalayan elevation patterns. We covered both plants and animals, and tested the hypothesis that unimodal gradients, explicable by the geometric mid-domain effect, prevail in the mountains, whereas decreasing or increasing gradients result from studying only short sections of entire altitudinal ranges. Multivariate canonical correspondence analysis was used to relate gradient shapes to their altitude ranges, geography positions, and taxa studied. Across taxa, most of the Himalayan altitudinal gradient display a unimodal shape, with a peak of diversity situated at ca 2500 m a.s.l. for plants, and 2200 m a.s.l. for animals. The gradient shapes were attributable to three intercorrelated predictors: vertical range, maximum elevation, and mean elevation of the gradients. Studies covering sufficiently broad altitudinal range returned unimodal gradients. Studies from the Earth’s highest mountain range reveal that surveys covering substantial parts of the elevational range of the mountains result in unimodal elevational gradients, whereas declining or increasing species richness gradients result from incomplete elevation range sampling.

Numerical simulation of uneven settlement of municipal solid waste landfill by FLAC 3D

After the landfill site is sealed, the uneven settlement is related to the safety of reutilisation of the site, and it is critical to calculate the uneven settlement of the site without error. In this article, the soil parameter of garbage body was changed with biodegradation. Fast Lagrangian Analysis of Continua in three dimensions (FLAC 3D) numerical simulation was applied to the settlement of the landfill site closure. In calculating the settlement of landfill, the soil parameters of landfill with age were obtained by field drilling experiments. The parameters can reflect the characteristics of soil organic matter in different biodegradation stages. Finally, the uneven settlement within 20 years of the closure period was obtained by the numerical simulation taking Jinzhou Nanshan landfill as an example. The results show that the settlement with the age increases gradually, but the rate will be more and more moderate, and the maximum subsidence value in the sealing field after 20 years will be 9.11 m, 15.71% of the maximum elevation. Around the landfill slope position of uneven settlement rate is bigger, and the maximum angle of uneven settlement is up to 45°. But the middle position is small, which is close to 0°.

The calculation of maximum elevation due to storm surge by using joint probability method

In the present paper the maximum storm surge elevations with certain return years were calculated by using a joint probability method. Based on the analyses of the typhoons which, affected coastal zone of Guangdong Province in history, a group of model typhoons was established. A number of parameters, which described the typhoons, were selected. The data of each parameter I was graded into a few sub-groups according to their values, and this was done in accordance with the historical observations. The probability of each value of the parameters was calculated based on the historical records. The probability of a typhoon with a group of values of parameters could be calculated. Simulation results of the storm surges caused by the above model typhoons with their probabilities were analysed statistically. Thus an accumulated probability curve and maximum elevations with certain return years were obtained. A number of spots was selected. At some of the spots there are tidal stations and at the others there are none. The maximum elevations with certain return years at the spots were calculated and the results were found satisfactory. By using this method all the meteorological and hydrological data, which were available, can be fully utilized. This method is most suitable for calculating the maximum elevations at a place where there is no tidal station or at many places simultaneously.

Skin Strain Analysis of the Scapular Region and Wearables Design

Monitoring scapular movements is of relevance in the contexts of rehabilitation and clinical research. Among many technologies, wearable systems instrumented by strain sensors are emerging in these applications. An open challenge for the design of these systems is the optimal positioning of the sensing elements, since their response is related to the strain of the underlying substrates. This study aimed to provide a method to analyze the human skin strain of the scapular region. Experiments were conducted on five healthy volunteers to assess the skin strain during upper limb movements in the frontal, sagittal, and scapular planes at different degrees of elevation. A 6 × 5 grid of passive markers was placed posteriorly to cover the entire anatomic region of interest. Results showed that the maximum strain values, in percentage, were 28.26%, and 52.95%, 60.12% and 60.87%, 40.89%, and 48.20%, for elevation up to 90° and maximum elevation in the frontal, sagittal, and scapular planes, respectively. In all cases, the maximum extension is referred to the pair of markers placed horizontally near the axillary fold. Accordingly, this study suggests interesting insights for designing and positioning textile-based strain sensors in wearable systems for scapular movements monitoring.

Unoccupied Aircraft Systems (UASs) Reveal the Morphological Changes at Stromboli Volcano (Italy) before, between, and after the 3 July and 28 August 2019 Paroxysmal Eruptions

In July and August 2019, two paroxysmal eruptions dramatically changed the morphology of the crater terrace that hosts the active vents of Stromboli volcano (Italy). Here, we document these morphological changes, by using 2259 UAS-derived photographs from eight surveys and Structure-from-Motion (SfM) photogrammetric techniques, resulting in 3D point clouds, orthomosaics, and digital surface models (DSMs) with resolution ranging from 8.1 to 12.4 cm/pixel. We focus on the morphological evolution of volcanic features and volume changes in the crater terrace and the upper part of the underlying slope (Sciara del Fuoco). We identify both crater terrace and lava field variations, with vents shifting up to 47 m and the accumulation of tephra deposits. The maximum elevation changes related to the two paroxysmal eruptions (in between May and September 2019) range from +41.4 to −26.4 m at the lava field and N crater area, respectively. Throughout September 2018–June 2020, the total volume change in the surveyed area was +447,335 m3. Despite Stromboli being one of the best-studied volcanoes worldwide, the UAS-based photogrammetry products of this study provide unprecedented high spatiotemporal resolution observations of its entire summit area, in a period when volcanic activity made the classic field inspections and helicopter overflights too risky. Routinely applied UAS operations represent an effective and evolving tool for volcanic hazard assessment and to support decision-makers involved in volcanic surveillance and civil protection operations.

Patterns of recent deformation of the western Maracaibo block, northern Colombia and western Venezuela, based on integration of geomorphic indices with regional geology

The Maracaibo block is a triangular, continental tectonic terrane that includes two isolated Andean ranges of northern Colombia and western Venezuela: the Sierra de Santa Marta Massif (SSMM; maximum elevation 5700 m) in the west and the Perija Range (PR; 3600 m) to the east. The Cesar-Rancheria Basin (CRB) is an intermontane basin that separates the two ranges. To establish patterns of recent deformation of this elevated region and to infer its tectonic mechanism, we have integrated the following results: (1) analysis of 350 stream profiles and calculations of geomorphic indices, including stream length-gradient (SL) index, ratio of valley-floor width to valley height (VF), and hypsometry curves for 20 watersheds in both ranges and (2) interpretation of three seismic reflection profiles within the CRB and adjacent areas. We determine that the northeastern part of the SSMM is tectonically quiescent based on its concave stream profiles, low geomorphic indices, and few vertical-step knickpoints. In comparison, we find that the central, southern, and eastern parts of the SSMM show tectonic uplift and recent fault control based on slope-break knickpoints and values in steepness and geomorphic indices with possible additional controls from lithologies of varying erosional resistance. Correlation among steepness, SL indices, slope-break knickpoints, and topographic elevations of the SSMM and central PR all indicate recent deformation of these areas. We use seismic reflection profiles from the eastern part of the CRB to confirm the existence of late Quaternary faulting and folding in these geomorphologically active areas. We think that active, southeastward shallow (approximately 10°–15°) subduction of the Caribbean plate along the base of the South American continental crust focuses recent deformation within the southern and eastern SSMM. The central PR and eastern CRB are also controlled by active strike-slip faults.

KERENTANAN TINGGALAN BUDAYA BAWAH AIR SITUS KARANG BUI DI PERAIRAN PANTAI UTARA JAWA BARAT

The Vulnerability of Underwater Cultural Heritages in Karang Bui Site, Northern Coast of West Java. Underwater remains which found in Karang Bui site, Karawang-Subang waters are originated from the colonial period of Vereenigde Oostindische Compagnie (VOC) and occupation period of the Kingdom of the Netherlands in Indonesia. Research on the vulnerability of the Karang Bui site has been conducted by the Ministry of Marine Affairs and Fisheries in 2017-2018. Research methods including observation of sea area; diving activities for site documentation, seabed profiles mapping, and the use of Side Scan Sonar. Besides looting activities that occurred in the past, the threats toward Karang Bui site preservation nowadays are from human and natural factors. Karang Bui site is located in shallow water with a depth of 5-12 m, so during the maximum elevation, the waves height and current velocity which forms at that location is increasing. Sedimentation level in Karang Bui site is also high caused by many rivers estuary around the site. The site is located within the area of P.T. Pertamina petroleum refineries which is likely the spill oil will threaten the archaeological remains. Furthermore, Karang Bui site is located near Patimban, Subang port development area which also the shipping line. Planning and protection measurement needs to be carried out immediately by related institutions and local governments. Thus, due those various vulnerability factors, the lifting of Karang Bui underwater artifacts is important to be done. Abstrak. Tinggalan bawah air yang ditemukan di Karang Bui, perairan Karawang-Subang, berasal dari masa Vereenigde Oostindische Compagnie (VOC) dan masa penjajahan Kerajaan Belanda di Indonesia. Penelitian terhadap kerentanan Situs Karang Bui telah dilakukan oleh Kementerian Kelautan dan Perikanan (KKP) pada tahun 2017-2018. Metode penelitian meliputi observasi kawasan laut, penyelaman bawah air untuk dokumentasi situs, pemetaan profil dasar laut, penggunaan side scan sonar. Selain aktivitas penjarahan pada masa lalu, ancaman terhadap kelestarian Situs Karang Bui saat ini berasal dari alam dan ulah manusia. Situs Karang Bui berada di perairan dangkal dengan kedalaman 5-12 m sehingga saat elevasi maksimal, tinggi gelombang dan kecepatan arus yang terbentuk di lokasi tersebut semakin meningkat. Tingkat sedimentasi di Situs Karang Bui juga tinggi karena banyak muara sungai di sekitar situs. Lokasi situs berada di area kilang-kilang pengeboran minyak bumi milik P.T. Pertamina, yang kemungkinan tumpahan minyak akan mengancam tinggalan arkeologis. Selain itu, lokasi situs berada di dekat area pembangunan Pelabuhan Patimban, Subang, juga merupakan alur pelayaran. Perencanaan dan tindakan pelindungan Situs Karang Bui perlu segera dilakukan oleh institusi terkait dan pemerintah daerah. Oleh karena berbagai faktor kerentanan tersebut, pengangkatan artefak bawah air Karang Bui sangat penting untuk dilakukan.

Sand Ridges on Rocky Coastal Platforms as Markers of Tsunami Impact: A Multi-Disciplinary Analysis along the Ionian Coast of Southern Apulia (Italy)

Along the Ionian coast of Southern Apulia, a sand ridge has been detected at the inner border of a wide, low-elevated rocky platform. A multi-disciplinary analysis was carried out to define the main geomorphological and sedimentological features of this dune-like coastal deposit, to clarify its nature as well as to obtain chronological constraints for its development. The geomorphological survey reveals that the sand ridge is about 40–60 m wide, reaching a maximum elevation of 3.9 m above m.s.l., whereas its thickness can be estimated between 1.0 and 2.8 m. The sand ridge is in some places associated with large-size boulders. Grain size analysis shows that it is made up of poorly sorted coarse-medium sands with a gravelly fraction, without significant sedimentary structures, as confirmed by Ground Penetrating Radar survey. The micro and macro-faunal assemblage sampled in the sand ridge can be related to shallow-water environments with Posidonia oceanica meadows occurring offshore. The development of the studied sand ridge can be ascribed to a tsunami event able to mix up very coarse bioclastic sands placed at submerged platforms, storm beach deposits covering the low-elevated coastal platform in patches, and possibly older tsunami deposits. Accelerator Mass Spectometry radiocarbon age determinations on mollusc shells sampled from the sand ridge span from 929–1168 AD to 1707–1950 AD and cluster around the 18th–19th centuries, suggesting a possible association with a recent tsunami event. Data reported in the Euro-Mediterranean Tsunami Catalogue would indicate as the most likely event that one of the 25th April 1836, produced by a strong earthquake with its epicenter near Rossano village, on the Ionian coast of the Calabria region.

Contrasting responses of land-terminating glaciers to recent climate variations in King George Island, Antarctica

In this study, we aim to analyse the glacier dynamics of land-terminating glaciers in King George Island (Antarctica) between 1956 and 2018. Glacial fluctuations are estimated using space-borne remote sensing data (SPOT, Landsat, PlanetScope, Sentinel-1, Sentinel-2, WorldView-2 and TanDEM-X). The eastern sector of Warszawa Icefield witnessed continuous glacier retreat during 1979–2018 (surface loss of 30%). The decreases in the ice-covered areas of the Tower, Windy, Ecology, Baranowski and Sphinx glaciers were 70%, 31%, 25%, 25% and 21%, respectively, with their accumulation area ratios (AARs) exhibiting negative mass balances. The winter air temperature was cooler during the 1970s with warming trends in the 1980s and early 2000s followed by a cooling trend until the present day. However, the annual time series has shown high interannual variability in air temperature during these periods. We show that the AAR, dimensions, length, frontal elevation, maximum elevation, slope and changes in the terminus position influence the glacier response to climate change at various timescales. Furthermore, three geomorphic activity intensity zones and a complete paraglacial sequence are identified while contrasting the proglacial systems. Overall, subglacial deposits predominate and indicate that meltwater flows on the bed, producing wet-based thermal regimes.

LOFAR 144-MHz follow-up observations of GW170817

ABSTRACT We present low-radio-frequency follow-up observations of AT 2017gfo, the electromagnetic counterpart of GW170817, which was the first binary neutron star merger to be detected by Advanced LIGO–Virgo. These data, with a central frequency of 144 MHz, were obtained with LOFAR, the Low-Frequency Array. The maximum elevation of the target is just 13${_{.}^{\circ}}$7 when observed with LOFAR, making our observations particularly challenging to calibrate and significantly limiting the achievable sensitivity. On time-scales of 130–138 and 371–374 d after the merger event, we obtain 3σ upper limits for the afterglow component of 6.6 and 19.5 mJy beam−1, respectively. Using our best upper limit and previously published, contemporaneous higher frequency radio data, we place a limit on any potential steepening of the radio spectrum between 610 and 144 MHz: the two-point spectral index $\alpha ^{610}_{144} \gtrsim$ −2.5. We also show that LOFAR can detect the afterglows of future binary neutron star merger events occurring at more favourable elevations.