Geological and Bioregional Assessments: a tale of two basins

The Australian Government’s $35.4 million Geological and Bioregional Assessment (GBA) Program is assessing the potential impacts of shale, tight and deep coal gas development on water and the environment in the Beetaloo, Isa and Cooper GBA regions. This paper compares the outcomes of impact assessments for the Beetaloo and Cooper GBA regions, highlighting the role that local geology, hydrogeology, ecology and regulatory regimes play when assessing potential impacts of unconventional gas development. Unconventional gas development activities between basins are broadly consistent, involving drilling, stimulation of the reservoir (typically through hydraulic fracturing), production and processing of hydrocarbons, export to market and decommissioning and rehabilitation. The characteristics of these activities and their potential impacts are strongly influenced by local factors including the geology, environment, industry practices and regulatory regimes. While subsurface impacts associated with hydraulic fracturing and well integrity are considered unlikely in both regions, regional geology means there is greater stratigraphic separation between target resources and overlying aquifers in the Beetaloo Sub-basin than in the Cooper Basin. Local ecological conditions and species influence the nature of potential impacts on protected matters in the two basins, which are mostly associated with surface disturbance and spills or accidental release of fluids. A key similarity between the two regions is the broadly consistent regulation and management of potential impacts in the two basins. Preliminary results of the causal network analysis indicate that mitigation measures are available for all pathways in which unconventional gas resource development activities may have the potential to impact on endpoints.

Repeated thinning treatments reduce long-term soil carbon and nitrogen storage: An 87-year study at the Petawawa Research Forest, Canada

Forest management activities are increasingly analyzed through a lens that quantifies their effects on soil carbon (C) and nitrogen (N) storage, because forest soils are an important C sink. Data on the longer-term impacts of repeated interventions are often lacking. At the Petawawa Research Forest, Ontario, treatments to evaluate the effect of repeated thinnings on wood quality of red and white pine were initiated in 1918 with the first experimental plots in Canada, permanent sample plot 1 (thinned) and 2 (control). In 2005, 16 years after the last thinning in 1989, we observed that repeated thinnings reduced soil C and N stocks in the surface L and F and Ah horizons. Contrary to our hypotheses, concentrations and stocks of C and N increased in the Bm1 horizon, indicating that these elements could be accumulated in deeper horizons after surface disturbance and potentially increased decomposition associated with thinning. However, total C and N accumulation in the profile to 30 cm contributed to reduced storage (-35 % for C, and -30 % for N). Many forest sites in the Great Lakes Forest Region that are selectively cut repeatedly over decades could experience this level of soil C and N decline.

Fairway Renovation with Fraise Mowing Cultivation and Dazomet Fumigation

Renovation is an opportune time for golf courses to address annual bluegrass (Poa annua L.) weed populations. Dazomet (tetrahydro-3,5-dimethyl-2H-1,3,5-thiadiazine-2-thione) is an effective fumigant, but without a tarp cover, it is only effective at the highest labeled rates. Fraise mowing cultivation could be used to help remove surface material and allow practitioners to effectively fumigate at lower rates. In Summer 2018 and Summer 2019, two cool-season fairway renovation experiments were conducted in East Lansing, MI. The objective of these experiments was to assess annual bluegrass control and creeping bentgrass establishment following dazomet applications to fraise mowed surfaces. In the first experiment (fraise mowing surface disturbance experiment), dazomet was applied at a fixed rate (294 kg·ha−1) to fraise mowed plots at varying levels of surface disturbance (0%, 15%, 50%, and 100%) to a depth of 1.9 cm. In the second experiment (dazomet rate experiment), fraise mowing removed 100% of surface material at a depth of 1.9 cm and dazomet was applied at five rates (0, 294, 588, 147 + 147, and 294 + 294 kg·ha−1). Both experiments were conducted on two soils (sand topdressed vs. native) and evaluated two methods of fumigant incorporation (solid-tine cultivation vs. tillage). Five days after treatments were applied, plots were seeded with ‘Pure Select’ creeping bentgrass (Agrostis stolonifera L.). The level of fraise mowing surface disturbance had no effect on annual bluegrass emergence, and creeping bentgrass cover was poorest in native soils at the highest levels of surface disturbance. In the dazomet rate experiment, dazomet applied twice at 294 kg·ha−1 provided the most consistent control of annual bluegrass. With the exception to single applications of 294 in 2018, all dazomet treatments allowed for greater creeping bentgrass establishment than the nontreated control. Fraise mowing cultivation may simplify the removal of surface material from large areas; however, even when combined with dazomet applied at the highest rates, it fails to provide complete annual bluegrass control.

Determination of Mortar Strength in Historical Brick Masonry Using the Penetrometer Test and Double Punch Test

This paper presents the results of the minor destructive testing of mortars in masonry structures of four buildings erected at the turn of the 19th and 20th centuries. The buildings were erected in the historical centre of Cracow. The objective of testing was to determine mortar compressive strength in masonry joints. The in situ tests were carried out with the use of a penetrometer RSM-15 with the standardised impact energy equalling 4.55 nm. Laboratory tests on mortar specimens taken from the structures were also performed. The double punch test method was used in the laboratory tests. On account of the specificity of the tested historical mortars, the typical procedures used in penetrometer and double punch tests were modified. For penetrometer tests, a new feature called “a surface disturbance zone” was introduced. Additionally, a procedure for determining a surface disturbance zone range was included. As confirmed in the paper, the consideration of the surface disturbance zone in the analysis of test results is crucial for the correct evaluation of mortar compressive strength. The thicknesses of bed joints in the tested historical masonry considerably exceeded the requirements included in the standard EN 1996-1-1. Thus, the thickness of the mortar specimens taken from historical masonry for the double punch tests clearly exceeded the thickness of specimens extracted from the typical structures erected nowadays. This article provides a method of considering a specimen thickness parameter in the analysis of double punch test results. The in situ test results with the use of penetrometer and double punch methods confirmed that the mortar strength in tested historical buildings ranged from 1.4 to 2.9 MPa. Mortar compressive strength values determined by both applied methods were similar.

UTILIZATION OF STATIONARY UNDERWATER SURVEILLANCE SYSTEMS FOR THE ESTIMATION OF UNDERWATER CURRENTS AND SEA DISTURBANCE PARAMETERS

Системы стационарного подводного видеонаблюдения, разработанные в ТОИ ДВО РАН, помимо решения задач наблюдения за состоянием морской биоты прибрежных акваторий залива Петра Великого (Японское море) могут применяться для оценивания характеристик морского волнения и подводных течений. Эти характеристики важны как в контексте сопровождения наблюдений за жизнедеятельностью морских организмов информацией о гидрологических условиях их существования, так и сами по себе – как важные параметры состояния природной среды. В статье рассмотрены несколько методик измерения сигналов вариаций подводных течений и оценивания на их основе частотных свойств поверхностного волнения. Основная идея состоит в отслеживании на основе анализа видео горизонтальных движений легких маркеров под воздействием на них течений. В первой части работы приведены примеры использования искусственных маркеров двух видов – закрепленных на тонкой нити теннисных шариков с небольшой положительной либо отрицательной плавучестью и установленных на дне вертушек. Показано, что при небольших глубинах установки камер частотные свойства сигналов горизонтальных движений маркеров хорошо воспроизводятся в сигналах поверхностного волнения в диапазонах ветровых волн, корабельных волн, волнения зыби, сейшевых колебаний уровня моря с периодами от десятков секунд до десятков минут. Во второй части работы рассмотрены технологии измерений, основанные на использовании естественных маркеров–полей органических и неорганических взвесей, перемещаемых водными потоками перед камерой, либо растительности, изменяющей свой наклон под действием течений. Они могут применяться при отсутствии либо выходе из строя искусственных маркеров. Stationary systems for underwater video surveillance designed in POI FEB RAS apart from solving tasks of marine biot monitoring in the off-shore strip of Peter the Great Bay can be used for estimating characteristics of sea disturbance and underwater currents. These characteristics are essential both for supplementing the observations of life activities of marine organisms with hydrological existence conditions and by itself, as vital parameters of environmental conditions. This work considers several methods of measuring signals of variations of underwater currents and estimating frequency properties of sea disturbance on its basis. The main idea is to track horizontal movements of light markers driven by underwater currents based on the video analysis. The first part of the article presents examples of the utilization of markers of two types: tennis balls with slightly positive or negative buoyancy mounted on thin thread and propellers mounted on the bottom. It is shown that at a small depth of the camera installation, the frequency properties of the signals of markers horizontal movements are easily reproduced in signals of sea surface disturbance in the range of wind waves, sea swells, seiche oscillations of the sea level with a period from tens of seconds to tens of minutes. The second part of the article considers technologies of measurements based on the utilization of natural markers, such as fields of organic and inorganic suspended matter moved by water streams in front of a camera or submerged vegetation, which inclination angle is changed under the influence of currents. These approaches can be used in the absence of artificial markers or their failure.

Virtual Replica of a Towing Tank Experiment to Determine the Kelvin Half-Angle of a Ship in Restricted Water

The numerical simulation of ship flows has evolved into a highly practical approach in naval architecture. In typical virtual towing tanks, the principle of Galilean relativity is invoked to maintain the ship as fixed, while the surrounding water is prescribed to flow past it. This assumption may be identified, at least partly, as being responsible for the wide-scale adoption of computational solutions within practitioners’ toolkits. However, it carries several assumptions, such as the levels of inlet turbulence and their effect on flow properties. This study presents an alternative virtual towing tank, where the ship is simulated to advance over a stationary fluid. To supplement the present work, the free surface disturbance is processed into Fourier space to determine the Kelvin half-angle for an example case. The results suggest that it is possible to construct a fully unsteady virtual towing tank using the overset method, without relying on Galilean relativity. Differences between theoretical and numerical predictions for the Kelvin half-angle are predominantly attributed to the assumptions used by the theoretical method. The methods presented in this work can potentially be used to validate free-surface flows, even when one does not have access to experimental wave elevation data.

Geologi Situs Paleolitik Pacitan Bagian Timur Kabupaten Pacitan, Provinsi Jawa Timur

The Geology of the Paleolithic Site of the Eastern Part of Pacitan, Pacitan Regency, East Java Province. The Paleolithic Site of the Eastern Part of Pacitan is located at Km-10 to Km-18 east of the city of Pacitan to the direction of Trenggalek regency. It covers three main rivers, namely Kedunggamping (Padi) River, Ngrendeng-Tulakan River, and Lorog River. The site has lowland, weak wavy, strong wavy, and karst morphological units. It is situated at an elevation of O - 900 m above sea level. The three rivers that flow in this area are old and old-mature stadium ones, with observable trellis and rectangular desiccated patterns. They belong to periodic, consequent, and subsequent types. The rocks that compose the area are volcanic breccia, conglomerate, ingenous rock unit, sand stone, tuff, clay-stone, silt, limestone unit, and alluvial sediment, with ages that range from Oligocene up to Holocene. The geological structures that are found in this place include sincline fold and strike slip. The river terraces belong to the first, which still directly connected to the river surface. Disturbance on geological structure is one of the factors that influence the position and existence of the river terraces. Lithic tools made of chert, andesite, jasper, silicified-limestone, wood fossil, chalcedony, and limestone are found at this site. The raw materials of those tools (granule, pebbles, and boulders) are usually available along the rivers.Abstrak. Lokasi Situs Paleolitik Pacitan bagian Timur terletak di Km-10 hingga Km-18 sebelah timur Kota Pacitan ke arah Kabupaten Trenggalek. Situs Paleolitik ini meliputi wilayah Sungai Kedunggamping (Sungai Padi), Sungai Ngrendeng-Tulakan, dan Sungai Lorog. Bentang alam wilayah situs ini termasuk pada satuan morfologi dataran, satuan morfologi bergelombang lemah, satuan morfologi bergelombang kuat, dan satuan morfologi karst. Ketinggian situs berada pada O - 900 meter di atas permukaan air laut. Ketiga sungai itu termasuk pada sungai berstadia Tua (old river stadium) dan Dewasa-Tua (old-mature), dengan kenampakan pola pengeringan Trellis dan Rectangular. Selain itu, termasuk pada Sungai Periodis, Sungai Konsekuen, dan Sungai Subsekuen. Batuan penyusun wilayah situs adalah breksi vulkanik, konglomerat, satuan batuan beku, batu pasir, tufa, batu lempung, batu lanau, satuan batu gamping, dan endapan aluvial. Kisaran umurnya ialah dari Oligosen hingga Holosen. Struktur geologi yang melewati wilayah situs adalah Lipatan (fold) dari jenis sinklin, dan Patahan (fault) dari jenis sesar geser. Undak-undak sungai yang teramati termasuk pada undak sungai pertama yang masih berhubungan langsung dengan muka air sungai. Gangguan struktur geologi ikut mempengaruhi keletakan dan keberadaan undak-undak sungai itu sendiri. Alat-alat litik terdiri dari batuan chert, andesit, jasper, batugamping kersikan, fosil kayu, kalsedon, dan batugamping. Sumber bahan baku alat-alat litik tersebut umumnya berada di alur-alur sungai dalam bentuk kerikil, kerakal, dan boulder batuan.