Studies in the Wanganui Series: Pliocene Foraminifera from Wanganui Basin

<p>Foraminifera have been examined from seven Pliocene sections in South Wanganui Basin, southern North Island, New Zealand, including the Waipipian and Mangapanian Stratotypes. Lithology, faunal distribution, biostratigraphy and paleoecology are discussed for each section. The systematics and ecologic and stratigraphic ranges of 193 species are discussed. The new genus Zelamarkina is erected, with Z. excavata n.sp. as type species, and the following five species are also described as new: Bolivina hornibrooki, B. vellai, B. wanganuiensis, Rotalia fastigata and Notorotalia briggsi. Three biostratigraphic zones based on benthonic foraminifera are recognised. The Hurupiensis Zone, defined by the range of Notorotalia hurupiensis in South Wanganui Basin, is considered equivalent to the Opoitian Stage. The Molestus Zone, defined by the overlapping ranges of Cibicides molestus and Notorotalia finlayi, represents the Waipipian Stage. The Finlayi Zone equals that part of the range of N. finlayi after the extinction of Cibicides molestus, and extends through to the Recent. Temperatures dropped abruptly and markedly at the time represented by the base of the Molestus Zone, accompanied by a substantial fall in sea level, then rose at the time represented by the end of this zone to a level maintained through the period studied. No marked temperature or sea level change is recorded across the presumed Pliocene-Pleistocene boundary. The region was covered during late Miocene and early Pliocene times by shallow seas, possibly with land to the west. Rapid subsidence of the centre of the basin during the early Pliocene was followed by gradual shallowing until by the late Pliocene uniformly shallow depths again pertained. The basin was bounded to the east by the emergent Ruahine and Tararua Ranges, and probably to the south and west by shallow bars or islands formed from uplifted basement blocks. The surface microstructure of nine species of Bolivina and seven species of Notorotalia is described from scanning electron micrographs. Addition of calcite to the test of Notorotalia is progressive and is controlled largely by the positions of sutural and apertural pores.</p>

Studies in the Wanganui Series: Pliocene Foraminifera from Wanganui Basin

<p>Foraminifera have been examined from seven Pliocene sections in South Wanganui Basin, southern North Island, New Zealand, including the Waipipian and Mangapanian Stratotypes. Lithology, faunal distribution, biostratigraphy and paleoecology are discussed for each section. The systematics and ecologic and stratigraphic ranges of 193 species are discussed. The new genus Zelamarkina is erected, with Z. excavata n.sp. as type species, and the following five species are also described as new: Bolivina hornibrooki, B. vellai, B. wanganuiensis, Rotalia fastigata and Notorotalia briggsi. Three biostratigraphic zones based on benthonic foraminifera are recognised. The Hurupiensis Zone, defined by the range of Notorotalia hurupiensis in South Wanganui Basin, is considered equivalent to the Opoitian Stage. The Molestus Zone, defined by the overlapping ranges of Cibicides molestus and Notorotalia finlayi, represents the Waipipian Stage. The Finlayi Zone equals that part of the range of N. finlayi after the extinction of Cibicides molestus, and extends through to the Recent. Temperatures dropped abruptly and markedly at the time represented by the base of the Molestus Zone, accompanied by a substantial fall in sea level, then rose at the time represented by the end of this zone to a level maintained through the period studied. No marked temperature or sea level change is recorded across the presumed Pliocene-Pleistocene boundary. The region was covered during late Miocene and early Pliocene times by shallow seas, possibly with land to the west. Rapid subsidence of the centre of the basin during the early Pliocene was followed by gradual shallowing until by the late Pliocene uniformly shallow depths again pertained. The basin was bounded to the east by the emergent Ruahine and Tararua Ranges, and probably to the south and west by shallow bars or islands formed from uplifted basement blocks. The surface microstructure of nine species of Bolivina and seven species of Notorotalia is described from scanning electron micrographs. Addition of calcite to the test of Notorotalia is progressive and is controlled largely by the positions of sutural and apertural pores.</p>

Pemantau Gas Metana, Suhu, dan Kelembaban sebagai Penyebab Efek Rumah Kaca Dipadang Lamun Berbasis Internet Of Things

Seagrass is a plant that covers coastal areas/shallow seas that can produce methane gas (CH4) during the decomposition process. The occurrence of decay caused by microbes in seagrass plants that have died in the process produces methane gas (CH4) as the cause of the greenhouse effect. Methane gas monitoring system (CH4) is proposed using MQ-4 sensor, temperature and humidity sensor (DHT11) using NodeMCU ESP8266 module, SD Card module as backup data storage and processed with local database and through mysql database the data will be displayed on the website page for information. . From the tests carried out, the response time for DHT11 is 5.6 seconds and MQ-4 is 1.5 seconds. It has a reading sensitivity rate of 99.92% for DHT11, 99.997% for MQ-4. The accuracy rate for DHT11 is a multiple of 1. For the MQ-4 sensor it has an accuracy level of 2 digits behind the comma. The tool has a data transfer rate of up to that which appears on the front-end 0.2736. With this tool, checking measurement results can be done quickly and can be done from anywhere.

Global shifts in species richness have shaped carpet shark evolution

Background The evolutionary processes that shape patterns of species richness in marine ecosystems are complex and may differ between organismal groups. There has been considerable interest in understanding the evolutionary processes that led to marine species richness being concentrated in specific geographical locations. In this study we focus on the evolutionary history of a group of small-to-medium sized sharks known as carpet sharks. While a few carpet shark species are widespread, the majority of carpet shark species richness is contained within a biodiversity hotspot at the boundary of the Indian and Pacific oceans. We address the significance of this biodiversity hotspot in carpet shark evolution and speciation by leveraging a rich fossil record and molecular phylogenetics to examine the prehistoric distribution of carpet sharks. Results We find that carpet sharks species richness was greatest in shallow seas connected to the Atlantic Ocean during the Late Cretaceous, but that there was a subsequent loss of biodiversity in Atlantic waters. Fossil evidence from sites in close geographic proximity to the current center of carpet shark diversity are generally restricted to younger geologic strata. Conclusions From this data we conclude that (1) center of carpet shark biodiversity has shifted during the last 100 million years, (2) carpet sharks have repeatedly dispersed to nascent habitat (including to their current center of diversity), and (3) the current center of carpet shark biodiversity conserves lineages that have been extirpated from this prehistoric range and is a source of new carpet shark species. Our findings provide insights into the roles of marine biodiversity hotspots for higher-tropic level predators and the methods applied here can be used for additional studies of shark evolution.

Research on underwater sound source ranging algorithm based on histogram filtering

Aiming at the distance measurement of moving sound sources in shallow seas, this paper proposes a method of histogram filtering to realize underwater distance estimation of moving sound sources in shallow seas. The algorithm used the transmission loss, target motion parameter in the sound propagation and receival signal as prior knowledge to updated the state vector of the sound source, so as to realize the distance estimation of the shallow sea sound source, and this paper used SwellEx-96 database for experimental verification. The experimental results shown that: the depth estimating error of moving sound source is small, and when the detected horizontal distance is in the range of 10 km, the maximum range error of the horizontal distance is ±10 m, meanwhile the accuracy of ranging can be improved by improving the prior knowledge of the target motion parameters, which verifies that the histogram filtering algorithm can achieve better ranging for underwater moving targets.

Performance of an Advanced Intelligent Control Strategy in a Dynamic Positioning (DP) System Applied to a Semisubmersible Drilling Platform

Oil drilling and extraction platforms are currently being used in many offshore areas around the world. Whilst those operating in shallow seas are secured to the seabed, for deeper water operations, Dynamic Positioning (DP) is essential for the platforms to maintain their position within a safe zone. Operating DP requires intelligent and reliable control systems. Nearly all DP accidents have been caused by a combination of technical and human failures; however, according to the International Marine Contractors Association (IMCA) DP Incidents Analysis, DP control and thruster system failures have been the leading causes of incidents over the last ten years. This paper will investigate potential operational improvements for DP system accuracy by adding a Predictive Neural Network (PNN) control algorithm in the thruster allocation along with a nonlinear Proportional Integral derivative (PID) motion control system. A DP system’s performance on a drilling platform in oil and gas deep-water fields and subject to real weather conditions is simulated with these advanced control methods. The techniques are developed for enhancing the safety and reliability of DP operations to improve the positioning accuracy, which may allow faster response to a critical situation during DP drilling operations. The semisubmersible drilling platform’s simulation results using the PNN strategy show improved control of the platform’s positioning.

Analysis of the interannual variability in satellite gravity solutions : impact of climate modes on water mass displacements across continents and oceans

&lt;p&gt;The acquisition of time-lapse satellite gravity measurements during the GRACE and GRACE Follow On (FO) missions revolutionized our understanding of the Earth system, through the accurate quantification of the mass transport at global and regional scales. Largely related to the water cycle, along with some geophysical signals, decadal trends and seasonal cycles dominate the mass transport signals, constituting about 80 % of the total variability measured during GRACE (FO) missions. We focus here on the interannual variability, constituting the remaining 20 % of the signal, once linear trends and seasonal signals have been removed. Empirical orthogonal functions (EOFs) highlight the most prominent signals, including short-lived signals triggered by major earthquakes, interannual oscillations in the water cycle driven by the El Nino Southern Oscillation (ENSO) and significant decadal variability, potentially related to the Pacific Decadal Oscillation (PDO). The interpretation of such signals remains however limited due to the arbitrary nature of the statistical decomposition in eigen values. To overcome these limitations, we performed a LASSO (Least Absolute Shrinkage and Selection Operator) regression of eight climate indices, including ENSO, PDO, NPGO (North Pacific Gyre Oscillation), NAO (North Atlantic Oscillation), AO (Arctic Oscillation), AMO (Atlantic Multidecadal Oscillation), SAM (Southern Annular Mode) and IOD (Indian Ocean Dipole). The LASSO regularization, coupled with a cross-validation, proves to be remarkably successful in the automatic selection of relevant predictors of the climate variability for any geographical location in the world. As expected, ENSO and PDO impact the global water cycle both on land and in the ocean. The NPGO is also a major actor of the global climate, showing similarities with the PDO in the North Pacific. AO is generally favored over NAO, especially in the Mediteranean Sea and North Atlantic. SAM has a preponderant influence on the interannual variability of ocean bottom pressures in the Southern Ocean, and, in association with ENSO, modulates the interannual variability of ice mass loss in West Antarctica. AMO has a strong influence on the interannual water cycle along the Amazon river, due to the exchange of moisture in tropical regions. IOD has little to no impact on the interannual water cycle. All together, climate modes generate changes in the water mass distribution of about 100 mm for land, 50 mm for shallow seas and 15 mm for oceans. Climate modes account for a secondary but significant portion of the total interannual variability (at maximum 60% for shallow seas, 50 % for land and 40% for oceans). While such processes are insufficient to fully explain the complex nature of the interannual variability of water mass transport on a global scale, climate modes can be used to correct the GRACE (FO) measurements for a significant part of the natural climate variability and uncover smaller signals masked by such water mass transports.&lt;/p&gt;