Northwestern Slope Research Articles

Paleochannels on the Northern Slope of the Derbent Basin, Caspian Sea

The results of studies in the paleochannel of the Volga River, which was discovered earlier on the northwestern slope of the Derbent Basin, Caspian Sea, are presented. Seismoacoustic profiling in the paleochannel, combined with placement of submerged buoy stations equipped with current gauges, water temperature gauges, and sediment traps showed that the channel is not silted and cold heavy water is transported along it to the deep sea part of the sea, avoiding the general water transit along the western coast of the Central Caspian Sea. The preliminary calculations show that water discharge through the channel to the near-bottom part of the sea can be about 8–10 km3/yr.

Dominant Circulation Patterns of the Deep Gulf of Mexico

AbstractThe large-scale circulation of the bottom layer of the Gulf of Mexico is analyzed, with special attention to the historically least studied western basin. The analysis is based on 4 years of data collected by 158 subsurface floats parked at 1500 and 2500 m and is complemented with data collected by current meter moorings in the western basin during the same period. Three main circulation patterns stand out: a cyclonic boundary current, a cyclonic gyre in the abyssal plain, and the very high eddy kinetic energy observed in the eastern Gulf. The boundary current and the cyclonic gyre appear as distinct features, which interact in the western tip of the Yucatan shelf. The persistence and continuity of the boundary current is addressed. Although high variability is observed, the boundary flow serves as a pathway for water to travel around the western basin in approximately 2 years. An interesting discovery is the separation of the boundary current over the northwestern slope of the Yucatan shelf. The separation and retroflection of the along-slope current appears to be a persistent feature and is associated with anticyclonic eddies whose genesis mechanism remains to be understood. As the boundary flow separates, it feeds into the westward flow of the deep cyclonic gyre. The location of this gyre—named the Sigsbee Abyssal Gyre—coincides with closed geostrophic contours, so eddy–topography interaction via bottom form stresses may drive this mean flow. The contribution to the cyclonic vorticity of the gyre by modons traveling under Loop Current eddies is discussed.

Glaciological settings and recent mass balance of Blåskimen Island in Dronning Maud Land, Antarctica

Abstract. The ice-shelf-fringed coast of Dronning Maud Land in East Antarctica contains numerous ice rises that influence the dynamics and mass balance of the region. However, only a few of these ice rises have been investigated in detail. Here, we present field measurements of Blåskimen Island, an isle-type ice rise adjacent to Fimbul Ice Shelf. This ice rise is largely dome shaped, with a pronounced ridge extending to the south-west from its summit (410 m a.s.l.). Its bed is mostly flat and about 100 m below the current sea level. Shallow radar-detected isochrones dated with a firn core reveal that the surface mass balance is higher on the south-eastern (upwind) slope than on the north-western (downwind) slope by ∼ 37 %, and this pattern has persisted for at least the past decade. Moreover, arches in radar stratigraphy suggest that the summit of the ice rise has been stable for ∼ 600 years. Ensemble estimates of the mass balance using the input–output method show that this ice rise has thickened by 0.12–0.37 m ice equivalent per year over the past decade.

Drivers of farmer satisfaction with small-scale irrigation systems

Climate change impacts the quantity and seasonality of rainfall, threatening Africans' ability to maintain satisfactory yields on rain-fed farms. On the semi-arid northwestern slopes of Mount Kenya, irrigation systems structured around Community Water Projects (CWPs) provide households with piped water, which helps mitigate drought impacts and enhances resilience to increasingly variable rainfall patterns. The vision of these irrigation systems is to equitably distribute water resources among CWP members both for household consumption and to maintain or improve agricultural yields. However, not all households receive equal quantities of water from their CWPs, and little is known about the impact of water provisioning on farmers' opinions or perceptions of CWP performance.In this study, we relate respondents' satisfaction with their CWPs to the quantity of water delivered. Not surprisingly, farmers who received low quantities of water from their CWPs expressed above-average rates of concern regarding drought. In contrast, satisfaction with one's CWP was unrelated to the absolute quantity of water received (log liters/minute), but it was strongly associated with relative measures of water delivery: respondents who received less water than other members of the same water project experienced high rates of dissatisfaction, as did respondents who received less water than in the past. These results suggest that Kenyan farmers may feel particularly dissatisfied—and, perhaps, particularly driven to demand improved water governance—when they perceive inadequate water delivery relative to some reference group.Because relative water quantity dictates satisfaction even after controlling for factors that can be resolved internally at the CWP level (by, for example, striving for uniformity of water flows across and within households), water project managers are limited to some degree in their ability to improve satisfaction through better governance. That said, governance actions that prevent declines in flows over time (e.g. maintaining infrastructure to reduce leaks) could ostensibly lead to meaningful improvements in member satisfaction.

Review: Santa Maria Antiqua tra Roma e Bisanzio, and Santa Maria Antiqua tra Roma e Bisanzio, by Maria Andaloro, Giulia Bordi, and Giuseppe Morganti

Santa Maria Antiqua tra Roma e Bisanzio , Santa Maria Antiqua, Rome, Italy. 17 March – 11 September, 2016. 8 December, 2016 – 19 March, 2017. Maria Andaloro, Giulia Bordi, and Giuseppe Morganti. Santa Maria Antiqua tra Roma e Bisanzio . Milan: Electa, 2016. 414 pages, ill. € 50. ISBN: 9788891807762 8891807761. In 2004 Leslie Brubaker made a rather somber joke about the church of Santa Maria Antiqua, saying that it had been the victim of “one hundred years of solitude,” an allusion the fact that, since the discovery of the church in 1900 by Giacomo Boni, its walls had been all but shut to the public.1 Recently, however, the church was the site of a major exhibition, thus ending that long period of isolation. Visitors were finally able to experience and study the medieval paintings, many of which were beautifully explained through a series of videos projected on the walls. The church has a history of hiding, even though it is in a very public and prominent part of Rome—along the northwestern slope of the Palatine Hill, in the southwestern zone of the Roman Forum. The church was first constructed at the end of the fifth century C.E. At least five popes were involved in decorating the church,2 often superimposing the frescoes from their campaign directly on top of previous ones. One famous example of this superimposition is the “palimpsest wall,” with its seven layers of paintings ( Fig. 1 ).3 The painting and repainting might have continued, but in 847 an earthquake destroyed so much of the church that it was abandoned. Ultimately covered by a Baroque church in 1617, the remains of Santa Maria Antiqua were all but forgotten. Scholars knew of the church from descriptions in the Liber Pontificalis , but it remained undiscovered until Boni's turn-of-the-century excavations. Fig. 1. Palimpsest Wall, Santa Maria Antiqua, Rome, Italy. Photo by Annie Labatt. Much research and conservation has been underway behind those closed doors since the discovery by Boni. However, the frescoes painted between the sixth to the ninth centuries were relatively unknown, which is ironic since hordes of visitors …

An early Emsian (Zlichovian) ammonoid assemblage from Sangibaland Mountain (Shakhimardan River Basin) (South Tien Shan, Kyrgyzstan)

Early Emsian (Zlichovian) ammonoids are recorded from a section of neritic deposits on the western and northwestern slopes of Sangibaland Mountain (right bank of the Shakhimardan River, near the village of Jiydelik, South Fergana, South Tien Shan, Kyrgyzstan) including other faunas such as conodonts, dacryoconarids, brachiopods, trilobites, and corals. The ammonoid fauna includes Erbenoceras cf. solitarium (Barrande, 1865), E. kimi Bogoslovsky, 1980 and new species of teicherticeratids. This combination of taxa allows the host beds to be correlated with the Zlichovian LDIII Zone. Ammonoids come from the Katran Formation, from beds previously recognised as the Sandal Formation, which is well–known for its neritic assemblages, interpreted as inhabitants of shallow shelf zones in the northern regions of the Paleozoic Alai–Tarim Terrane. Near the end of the Zlichovian, when the Dalejan transgression spread to the Sangibaland Region, ammonoids colonised the neritic basin near a carbonate platform, already inhabited by abundant benthic fauna. The co-occurrence of neritic and pelagic organisms is a useful feature providing a basis for the correlation between the pelagic and neritic successions of the lower Emsian (Zlichovian).

Stemodia cipoensis (Plantaginaceae): A New Species from Serra do Cipó, Minas Gerais, Brazil

Abstract The Serra do Cipo, part of the central portion of the Espinhaco Range in Minas Gerais, Southeast Brazil, is known to have been extensively investigated over the past three decades, especially because of the “Flora da Serra do Cipo” project. Nevertheless, some areas have been poorly collected as the efforts were largely concentrated near the roads. Various new species, in several families, have been recently discovered in the campos rupestres of the Serra do Cipo. Here we report the discovery of a new species of Stemodia (Plantaginaceae) from the northwestern slopes. We describe and illustrate the new species based on morphological and micro-morphological evidence, provide information on its taxonomy, habitat, geographical distribution, and conservation status, along with a key to distinguish it from the related species. Stemodia cipoensis is similar to S. harleyi, S. lobata, and S. stellata, being characterized by the presence of long, stiff, curved, eglandular trichomes. It has been assessed as ...

Use of a rostral appendage during social interactions in the Ecuadorian Anolis proboscis

ABSTRACTThe use of sexually selected characters in inter- and intra-sexual interactions has long been of interest to evolutionary biologists. Recently, a distinction between sexually selected traits as ornaments versus weapons has been advanced. We investigated the behaviour of an enigmatic lizard with a prominent sexually dimorphic trait in an effort to describe whether the trait was the product of sexual selection and further whether it functioned as a weapon or an ornament. The subject of our study was the Ecuadorian proboscis anole (Anolis proboscis), a slow-moving cryptic species endemic to the north-western slopes of the Andes in Ecuador. Males, but not females, of this species bear a rostral appendage that has been described as an exaggerated trait resulting from sexual selection. However, a thorough description of the use of the rostral appendage in social interactions is lacking. Here, we describe social interactions of this species during 11 male–female courtships and mating interactions, as well as three male–male agonistic interactions. We describe four types of displays by males, many involving the rostral appendage. We found that the rostral appendage is used as an ornament in social displays but not as a weapon in combat. We also show that, unlike other lizards with rostral appendages, male A. proboscis hatch with this structure already developed.

Explosive eruption, flank collapse and megatsunami at Tenerife ca. 170 ka

Giant mass failures of oceanic shield volcanoes that generate tsunamis potentially represent a high-magnitude but low-frequency hazard, and it is actually difficult to infer the mechanisms and dynamics controlling them. Here we document tsunami deposits at high elevation (up to 132 m) on the north-western slopes of Tenerife, Canary Islands, as a new evidence of megatsunami generated by volcano flank failure. Analyses of the tsunami deposits demonstrate that two main tsunamis impacted the coasts of Tenerife 170 kyr ago. The first tsunami was generated during the submarine stage of a retrogressive failure of the northern flank of the island, whereas the second one followed the debris avalanche of the subaerial edifice and incorporated pumices from an on-going ignimbrite-forming eruption. Coupling between a massive retrogressive flank failure and a large explosive eruption represents a new type of volcano-tectonic event on oceanic shield volcanoes and a new hazard scenario.

The use of remote sensing metods for determination of the thermal characteristics of the Ukrainian Carpatthians

The was shown the possibility of use remote sensing data for determination of thermal characteristics of the Ukrainian Carpathians. It was found that the lowest temperature of the earth’s surface is not observed on the tops of the mountains but on their northern and northwestern slopes.

Genetic affinities of a remnant population of the brush-tailed rock-wallaby (Petrogale penicillata) in Mt Kaputar National Park, northern New South Wales

The brush-tailed rock-wallaby (Petrogale penicillata) is now extinct west of the Great Dividing Range, apart from remnant populations in the Warrumbungles and at Mt Kaputar. Previous genetic analysis has identified deep genetic subdivisions within P. penicillata, but samples from Mt Kaputar were not included. Mitochondrial DNA sequences obtained from Mt Kaputar and the Warrumbungles clustered within the Central ESU, extending its distribution north of the Hunter River onto the north-western slopes adjacent to populations of the Northern ESU. These highly threatened western populations are the only P. penicillata persisting in semiarid conditions. This makes them of particular value to the long-term survival of the species and their conservation should be a priority.

Authigenic carbonates from newly discovered active cold seeps on the northwestern slope of the South China Sea: Constraints on fluid sources, formation environments, and seepage dynamics

Authigenic carbonates recovered from two newly discovered active cold seeps on the northwestern slope of the South China Sea have been studied using petrography, mineralogy, stable carbon and oxygen isotopic, as well as trace element compositions, together with AMS 14C ages of shells of seep-dwelling bivalves to unravel fluid sources, formation conditions, and seepage dynamics. The two seeps (ROV1 and ROV2), referred to as ‘Haima seeps’ herein, are approximately 7 kilometers apart, and are typified by abundant carbonate rocks represented bycrusts and nodules. Aragonite and high-Mg calcite are the main carbonate minerals. Based on low δ13Ccarbonate values ranging from −43.0‰ to −27.5‰ (V-PDB) methane is apparently the predominant carbon source of seep carbonates. The corresponding δ18O values, varying from 2.5‰ to 5.8‰ (V-PDB), mostly are higher than calculated values representing precipitation in equilibrium with seawater (2.5‰ to 3.8‰), which probably reflects past destabilization of locally abundant gas hydrates. In addition, we found that carbonates with bivalve shells are generally aragonite-dominated, and bear no barium enrichment but uranium enrichments, reflecting shallow formation depths close to the seafloor. In contrast, carbonate crusts without bivalve shells and nodules contain more calcite, and are characterized by major molybdenum enrichment and different degrees of barium enrichment, agreeing with precipitation at greater depth under strictly anoxic conditions. AMS 14C ages suggest that a major episode of carbonate precipitation occurred between 6.1 ka and 5.1 ka BP at the Haima seeps, followed by a possibly subordinate episode from approximately 3.9 ka to 2.9 ka BP. The common occurrence of dead bivalves at both sites indicates that chemosynthesis-based communities flourished to a greater extent in the past, probably reflecting a decline of seepage activity in recent times. Overall, these results confirm that authigenic carbonates from gas hydrate-bearing areas can provide insight into long-term seepage dynamics and the genesis and fate of marine gas hydrate reservoirs.

A2-03 霧島山北西部の上下変動 : えびの高原～えびの水準測量成果(2011年2月-6月)(新燃岳2011年噴火,口頭発表)

A2-03 霧島山北西部の上下変動 : えびの高原～えびの水準測量成果(2011年2月-6月)(新燃岳2011年噴火,口頭発表)

Recent decadal glacier mass balances over the Western Nyainqentanglha Mountains and the increase in their melting contribution to Nam Co Lake measured by differential bistatic SAR interferometry

The Western Nyainqentanglha Mountains locates in the southeastern center of the Inner Tibetan Plateau (ITP). Glaciers in this region are influenced by both the continental climate of Central Asia and the Indian Monsoon system. Their melting on the western slopes feeds the Nam Co Lake, which is the second largest endorheic lake in the ITP. The elevation of Nam Co Lake increased at a rate of 0.25±0.12myear−1 from 2003 to 2009. In this study, aimed at quantifying the decadal glacier mass balance in the Western Nyainqentanglha Mountains and their increasing melting contribution to Nam Co Lake; we applied the differential Bistatic SAR interferometry method to five pairs of TanDEM CoSSC datasets observed between 2013 and 2014 and SRTM acquired in 2000. The mean annual mass loss rate was −0.235±0.127mw.e.year−1 for the entire range. The mass loss rate for the northwestern slope (inside the Nam Co Lake drainage basin) and the southeastern slope (outside the Nam Co Lake drainage basin) were −0.268±0.129mw.e.year−1 and ¬0.219±0.126mw.e.year−1, respectively. Our results agree well with previous fieldwork at the Zhadang and Gurenhekou glaciers located on the northwestern and southeastern slopes. Debris-cover suppressed glacier downwasting to some extent. By presuming that all of the melted ice flows into the lake, the glaciers' melting contribution to Nam Co Lake's increasing water volume was approximately 10.50±9.00% during the period between 2003 and 2009.

LANDSLIDES ON MOUNT TREBEVIĆ SLOPES – ANALYSIS OF THE RESEARCH RESULTS

The study area is located on the northwestern slopes of Mount Trebević, in a densely populated area. Based on previous research at slope parts of Trebević, three complex with large-scale landslides wereidentified (landslide of Hambina Carina, landslide of Mrakuša and Trebevićka Street landslide-expanding complex) and there were observed also landslides of Soukbunar and Jewish cemetery. By the research conducted during 2014, drilling of exploratory wells was carried out, as well as engineering-geological and geotechnical investigations and laboratory testing of samples of soil and rocks that are a continuation of earlier started researches. By the research, there has been collected enough data to create a study on engineering-geological and geotechnical characteristics of the terrain and for the purposes of the regulatory plan (RP) "Soukbunar". After realization of the planned work, it was approached to drawing up of elaborate and database for objects.

The evolution of slump-induced destruction of Kukuy Griva slope (Lake Baikal) revealed on the base of the data of seismic and acoustic surveys

As a result of careful interpretation of the data of recent seismo-acoustic surveys, two major seismic complexes were identified in the structure of the upper sedimentary section of the north-western slope of Kukuy Griva (ridge). They are composed of several inner seismo-facies, which are very characteristic and separated with well-expressed regional reflector. Seismic and acoustic data revealed evidences of numerous landslide processes which were different in age and peculiarities of manifestation. For the first time, detailed schemes of seismo-facies distribution are compiled for major seismic complexes at the area. The boundary between seismic complexes is dated as 150 thousands years. It is shown that sliding was more intensive during Late Pleistocene and Holocene, reflecting activation of tectonic movements in this part of Baikal rift system.

The evolution of slump-induced destruction of Kukuy Griva slope (lake Baikal) revealed on the base of the data of seismic and acoustic surveys

As a result of careful interpretation of the data of recent seismo-acoustic surveys, two major seismic complexes were identified in the structure of upper sedimentary section of the north-western slope of Kukuy Griva (ridge). They are composed of several very characteristic inner seismo-facies and separated by well-expressed regional reflector. Seismic and acoustic data revealed evidences of numerous landslide processes which were different in age and peculiarities of manifestation. For the first time, detailed schemes of seismo-facies distribution are compiled for both major seismic complexes. The boundary between seismic complexes is dated as 150 thousands years. It is shown that sliding was more intensive during Late Pleistocene and Holocene, reflecting activation of tectonic movements in this part of Baikal rift system.

Development and Application of HAIMA (ROV)

As the main research result of Chinese national 863 plan project titled "deep-sea operation system in water depth of 4500 m" , China’s first ROV named "HAIMA" carried by "Ocean 6" had successfully passed the sea-trial in the South China Sea in 2014 by through three segments, and seventeen diving tasks with the maximum diving water-depth of 4502 m. After that, "HAIMA" was deployed rapidly, and won the first battle in the investigation of gas hydrate in the South China Sea. And for the first time, "HAIMA" revealed the presence of "cold spring" on the northwestern slope of the South China Sea, which indicated the existence of gas hydrate resources in this area, and achieved double breakthroughs in both application of domestic high-tech deep-sea devices and exploration of gas hydrate in the South China Sea. Leading by the search results of "HAIMA" , the first hydrate sample with high purity was obtained in the "cold spring" area, which was another big breakthrough for our country in the related research field. All the results showed that HAIMA worked in a good state, and had outstanding controls, reliability, stability and extended functions, which had fulfilled the standard for practical equipment. "HAIMA" filled in the blank of Chinese deep-sea exploration devices, and greatly improved the Chinese deep-sea equipment level and operation capability. "HAIMA" gained vital breakthrough for a series of key technologies and accomplished the same level of international similar ROVs, which had milestone meaning in the field of Chinese deep-sea device research.

Using hydrochemical data to estimate the components of the water balance (the Bodrak river basin, southwestern Crimea)

The assessment of the individual elements of the water balance in the catchment area of a small river was made. The water balance equation of Bodrak Basin (north-western slopes of the Crimean Mountains) based on hydro-chemical data was proposed. When calculating the incoming articles of precipitation the authors used data of the weather station located in the village Pochtovie. The corrections to the vertical zoning were inputted when calculating. Estimation of the condensation flow was based on long-term observations of the karst spring during the low-flow period. Estimations of evaporation were based on the calculation methods, recommended in the special publications.

Geomorphological Inventory as a Tool for Proclaiming Geomorphosite (a Case Study of Mt. Myslivna in the Novohradské hory Mts.— Czech Republic)

The study locality of Mt. Myslivna within the Novohradske hory Mts. (Czech Republic) represents an area which had restricted access prior to 1989. Detailed geomorphological inventory carried out in years 2002–2010 revealed prominent rock landforms developed within late Variscan, Weinsberg-type granite. Destructive as well as accumulative rock landforms were mapped with the use of GPS and include two cryoplanation platform, three frost-riven cliffs, three tors, two low exfoliation domes, two castle koppies, two blockfields, one relic of tor and smaller forms, such as rock ledges and laths. A distinct fissure system that shapes the rock relief consists of two sets of fissures: The primary set is formed by dominant fissures with NE-SW orientation accompanied by fissures with NW-SE orientation; the secondary set comprises of fissures oriented in ENE-WSW and NNW-SSE directions. The north-western slopes of Mt. Myslivna were declared a natural monument in 1992 due to natural beech woodland vegetation. However, the extent of the protected area does not include qualitatively as well as quantitatively the unique rock landforms on the southern slopes of Mt. Myslivna. Therefore, this research led to declaration of this site as a ‘Geomorphologically Significant Locality’ (Geomorphosite) in 2010. In addition, a proposal for extension of the natural monument boundary has been submitted.