Distribution of Holocene Marine Mud and Its Relation to Damage from the 1923 Earthquake Disaster in the Tokyo Metropolitan Area, Japan

Tokyo, which is located near the boundary between the North American and Philippine Sea plates, has been frequently struck by large earthquakes throughout the Holocene. The 1923 Taisho Kanto Earthquake is a rare historical earthquake that can be reconstructed in detail because abundant datasets were collected by investigations performed just after the earthquake. We examined 13,000 borehole logs from the Tokyo and Nakagawa lowlands to clarify the distribution and thickness of incised-valley fills and soft marine mud that had accumulated since the Last Glacial Maximum (LGM) on a grid with a resolution of 150 m × 150 m. We compared these datasets with the distribution of wooden house damage ratios caused by the Taisho Kanto Earthquake. Our results showed that the thickness of the soft mud, but not that of the incised-valley fills, was strongly correlated with the wooden house damage ratio. The mud content was >60%, water content was >30%, and S-wave velocity was ca. 100 m/s in the soft Holocene marine mud. The wooden house damage ratio was highest where the soft mud thickness was 20 m, because in those areas, both the soft mud and the wooden houses resonated with a natural period of ca. 1 s.

Kombinasi Perlakuan Lumpur Laut dan Pupuk Kandang untuk Pertumbuhan dan Produksi Sawi Sendok (Brassica rapa L) pada Tanah Ultisol

Organic fertilizers have an important role in the success of vegetable cultivation. Marine mud contains a lot of nutrients and organic matter, so it is useful for improving degraded soils in the short term and a source of nitrogen and minerals (especially Ca and Mg) in the long term. This study aimed to examine and explain the effect of doses of cow dung fertilizer and marine mud, for the growth and yield of spoon mustard (Brassica rapa L). This research was conducted at the Plastic House of the Faculty of Agriculture, Pattimura University, from June to August 2018. The experiment in this study was a factorial experiment in a completely randomized design with two factors. The first factor was sea mud from Tulehu Village (L) with 4 levels, namely: without sea mud (control), 100 g, 200 g and 300 g per kg of soil. The second factor was cow manure (K) with 4 levels, namely: without cow manure (control), 5 g, 10 g. and 15 g per kg of soil. The variables observed included plant height, leaf number, leaf area, plant biomass fresh weight, crown fresh and root fresh weight. Data were analyzed using Analysis of Variance (ANOVA) and further test using Duncan's test at 0.05 level. The results showed that the sea mud treatment had a very significant effect on the variables of plant height (3, 4 and 5 weeks after planting, WAP), leaf number (4 and 5 WAP), leaf area, plant biomass weight and plant crown weight, number of leaves (3 WAP) and root weight, but had no significant effect on plant height at age (1 and 2 WAP), and number of leaves (1 and 2 WAP). The treatment of cow dung fertilizer had a very significant effect on the variables of plant height (2, 4 and 5 WAP), number of leaves (3 and 5 WAP), plant biomass weight and plant crown weight, a significant effect on plant height (3 WAP), leaf number (4 WAP), but had no significant effect on plant height (1 WAP), leaf number (1 and 2 WAP), leaf area and root weight of plants. The interaction between the treatment of marine mud and cow manure gave a very significant effect on plant height (4 and 5 WAP), but there was no interaction on the other observation variables. Keywords: cow manure, marine mud, ‘spoon’ mustard, Ultisol soil ABSTRAK Pupuk organik mempunyai peranan penting terhadap keberhasilan budidaya tanaman sayuran. Endapan lumpur laut banyak mengandung unsur hara dan bahan organik, sehingga bermanfaat untuk memperbaiki tanah-tanah terdegradasi untuk jangka pendek dan sumber nitrogen dan mineral (khususnya Ca dan Mg) untuk jangka waktu panjang. Penelitian ini bertujuan untuk menguji dan menjelaskan pengaruh dosis pupuk kotoran sapi dan dosis lumpur laut untuk pertumbuhan dan produksi tanaman sawi sendok (Brassica rapa L). Penelitian ini dilaksanakan di Rumah Plastik Fakultas Pertanian, Universitas Pattimura dari bulan Juni sampai Agustus 2018. Percobaan dalam penelitian ini merupakan percobaan faktorial dalam Rancangan Acak Lengkap dengan dua faktor. Faktor pertama adlah lumpur laut (L) dari desa Tulehu dengan 4 taraf, yaitu: tanpa lumpur laut (kontrol), 100 g, 200 g dan 300 g per kg tanah. Faktor kedua adalah pupuk kotoran sapi (K) dengan 4 taraf, yaitu: tanpa pupuk kotoran sapi (kontrol), 5 g, 10 g. dan 15 g per kg tanah. Variabel yang diamati meliputi tinggi tanaman, jumlah daun, luas daun, bobot segar biomassa tanaman, bobot segar tajuk tanaman dan bobot segar akar tanaman. Data dianalisis menggunakan Analisis of Varians (ANOVA) dan uji lanjut menggunakan uji Duncan pada taraf 0,05. Hasil penelitian menunjukkan bahwa perlakuan lumpur laut berpengaruh sangat nyata terhadap variable tinggi tanaman (3, 4 dan 5 minggu setelah tanam, MST), jumlah daun (4 dan 5 MST), luas daun, bobot biomassa tanaman dan bobot tajuk tanaman, berpengaruh nyata terhadap jumlah daun (3 MST) dan bobot akar tanaman, tetapi berpengaruh tidak nyata terhadap tinggi tanaman umur (1 dan 2 MST), dan jumlah daun (1 dan 2 MST). Perlakuan pupuk kotoran sapi berpengaruh sangat nyata terhadap variable tinggi tanaman (2, 4 dan 5 MST), jumlah daun (3 dan 5 MST), bobot biomassa tanaman dan bobot tajuk tanaman, berpengaruh nyata terhadap tinggi tanaman (3 MST), jumlah daun (4 MST), tetapi tidak berpengaruh nyata terhadap tinggi tanaman (1 MST), jumlah daun (1 dan 2 MST), luas daun dan bobot akar tanaman. Interaksi antara perlakuan lumpur laut dan pupuk kotoran sapi memberikan pengaruh sangat nyata terhadap tinggi tanaman (4 dan 5 MST), namun tidak ada interaksi pada variable pengamatan lainnya. Kata kunci: lumpur laut, pupuk kotoran sapi, sawi sendok, tanah Ultisol.

A Novel Method with Stacking Learning of Data-Driven Soft Sensors for Mud Concentration in a Cutter Suction Dredger

The dredger construction environment is harsh, and the mud concentration meter can be damaged from time to time. To ensure that the dredger can continue construction operations when the mud concentration meter is damaged, the development of a dredger with advantages of low price and simple operation that can be used in emergency situations is essential. The characteristic spare mud concentration meter is particularly critical. In this study, a data-driven soft sensor method is proposed that can predict the mud concentration in real time and can mitigate current marine mud concentration meter malfunctions, which affects continuous construction. This sensor can also replace the mud concentration meter when the construction is stable, thereby extending its service life. The method is applied to two actual construction cases, and the results show that the stacking generalization (SG) model has a good prediction effect in the two cases, and its goodness of fit R2 values are as high as 0.9774 and 0.9919, indicating that this method can successfully detect the mud concentration.

A shallow mud volcano in the sedimentary basin off the Island of Elba

<p>The Island of Elba, located in the westernmost portion of the northern Cenozoic Apennine belt, is formed by metamorphic and non-metamorphic units derived from oceanic (i.e. Ligurian Domain) and continental (i.e. the Tuscan Domain) domains stacked toward NE during the Miocene.</p><p>Offshore, west of the Island of Elba, magnetic and gravimetric data suggest the occurrence of N-S trending ridges that, for the very high magnetic susceptibility, have been interpreted as serpentinites, associated with other ophiolitic rocks. Moving towards south in Tuscan domain, along N-S fault, there is clear evidence of off-shore gas seepage (mainly CH<sub>4</sub>), which can be related to recent extensional activity.</p><p>In this contest, a cold methane seep was discovered in the sedimentary basin off Elba Island, characterized by typical mud volcanoes conditions. Generally, mud volcanoes are the shallow expression of subsurface processes characterized by movements of large masses of sediments and fluids. A marine mud volcanoes is a window into different depth levels of the submerged geosphere where hydrogen sulfide, methane and other hydrocarbon-rich fluid seepage occurs caused by tectonic activity. Indeed, vertical migration of geogas, especially CH<sub>4</sub> from the reservoir strata to the sea floor occurs along focused, permeable migration pathways, often created by faults and fractures.</p><p>The sampled gas chemistry is typical of mud volcanoes, with methane as the prevalent gas component (>95 vol%) and minor gases that include carbon dioxide, nitrogen and trace amounts of helium. The combined stable C and H isotope composition of CH<sub>4</sub> (δ<sup>13</sup>C and δ<sup>2</sup>H) highlights a thermogenic origin of fluids discharged from mud volcano, contrary to likely abiotic origin gas found in the Pomonte seep and linked to serpentinized ultramafic rock systems.</p><p>The samples collected on this mud volcano are extremely depleted in <sup>3</sup>He and their <sup>3</sup>He/<sup>4</sup>He ratios are typical for a geological setting in which radiogenic crustal helium is strongly predominant. On the contrary, the Pomonte ophiolitic gas seeps show a mantle-derived <sup>3</sup>He-rich component estimated in the range between 10 and 15%.</p><p>Petrological data highlight the presence of siltites and marly mudstones characterized by different origin than those found on neighboring islets (shallow marine organogenic limestones); therefore, the possibility that the fragments of rock blocks, found in the mud volcano area, derive form erosional processes of the islet is discarded. The conical shapes highlighted by the multibeam echosounder are very similar to the typical backscatter signature of other mud volcanoes, thus confirming the possibilities of classify this site as mud volcano. Indeed, already during the scuba diving survey that allowed sampling gas and sediment, it was clearly observed and documented as a mud volcano.</p>

Records of Holocene climatic fluctuations and anthropogenic lead input in elemental distribution and radiogenic isotopes (Nd and Pb) in sediments of the Gulf of Lions (Southern France)

Marine mud belts represent potential continuous high-resolution climatic, environmental and anthropogenic archives. In this study, a geochemical record of the Gulf of Lions mud belt, which receives sediments from the Rhône watershed and to a lesser extent from the Languedoc region, is reported from Core KSGC-31. The effects of natural climatic changes and possible anthropogenic disturbances on Holocene sedimentation were ascertained by analysing sedimentation rates, chemical weathering (Al2O3/K2O) and sediment-source shifts (neodymium isotopic ratios; εNd). Measurements of elemental and isotopic lead were used to trace the source and determine the potential vectors of anthropogenic contaminations over the Holocene. High εNd values, recorded from 9000 to 3000 calibrated annum before present (cal. a BP) and around 1500 and 600 cal. a BP, are interpreted as an increase in sediment transport from the Alpine crystalline massifs to the sea induced by enhanced hydro-sedimentary conditions upstream. During the early and middle Holocene, low and stable weathering conditions were persistent, while the late Holocene was characterized by higher and more fluctuating weathering conditions. Sudden changes in the 206Pb/207Pb ratio observed during the Roman and Medieval periods suggest clear shifts in lead source from a natural Holocene background to late Holocene anthropogenic contaminations. Even though those shifts are coeval with atmospheric lead contaminations from Spain and Germany recorded in several sediment and ice archives, the local origin (the Cévennes) and the fluvial contamination is more likely in these cases. Those findings are contemporaneous with historical mining records in the Cévennes and point to an intensification of the merchant shipping.

Pengujian Sludge Battery Dengan Teknologi Microbial Fuel Cell Sebagai Sumber Energi Listrik Terbarukan

ABSTRACTMicrobial Fuel Cells are devices which convert chemical energy into electrical energy through catalytic reactions by microorganisms. In this study, the potential of electricity in MFC will be analyzed by using samples of sea mud, lake mud, land mud, and river mud. While the method used in this study is one series connected vessel, two vessels connected series with mud-water, two mud-mud series vessels, and the stack series method. The highest electrical conductivity produced by river mud reaches 3.63 mS/cm, while the lowest is lake mud with a conductivity value of 0.35 mS/cm. The highest electric power density produced by river mud by the two mud-mud vessel method is 46.766 mW/m2, while the lowest electrical power density in lake mud is 18.040 mW/m2. The highest electrical power is produced by river mud through a single vessel series system with a maximum power of 7.26 mW, while the lowest power is found in marine mud with a system of two mud-water vessels which is equal to 0.30 mW. The pattern of increase in voltage or current produced by the battery sludge is on average until the 7th day, then a decrease occurs until the last day of testing. The greatest potential for electrical energy is obtained by river mud using a single vessel series system with a maximum voltage of 5.38 V and lasting up to 14 days.Keyword : electric power density, microbial fuel cells, sludge battery