Wilujeng, Nuning Catur Sri; Lan, Yu-Ju
This study was aimed to investigate (1) the improvement of CFL elementary-school students' skill in learning Mandarin Chinese (hereafter referred to as Mandarin) vocabulary through creating comic without online resources, creating online comics individually and collaboratively; (2) the CFL elementary-school students' attitude towards the…
Hidalgo, William; Chandran, Jima N; Menezes, Riya C; Otálvaro, Felipe; Schneider, Bernd
Phenylphenalenones, polycyclic aromatic natural products from some monocotyledonous plants, are known as phytoalexins in banana (Musa spp.). In this study, (1) H nuclear magnetic resonance (NMR)-based metabolomics along with liquid chromatography and mass spectrometry were used to explore the chemical responses of the susceptible 'Williams' and the resistant 'Khai Thong Ruang' Musa varieties to the ascomycete fungus Mycosphaerella fijiensis, the agent of the black leaf Sigatoka disease. Principal component analysis discriminated strongly between infected and non-infected plant tissue, mainly because of specialized metabolism induced in response to the fungus. Phenylphenalenones are among the major induced compounds, and the resistance level of the plants was correlated with the progress of the disease. However, a virulent strain of M. fijiensis was able to overcome plant resistance by converting phenylphenalenones to sulfate conjugates. Here, we report the first metabolic detoxification of fungitoxic phenylphenalenones to evade the chemical defence of Musa plants.
Chakraborty, Pinaki; Gioia, Gustavo; Kieffer, Susan W
A strong volcanic plume consists of a vertical column of hot gases and dust topped with a horizontal 'umbrella'. The column rises, buoyed by entrained and heated ambient air, reaches the neutral-buoyancy level, then spreads radially to form the umbrella. In classical models of strong volcanic plumes, the plume is assumed to remain always axisymmetric and non-rotating. Here we show that the updraught of the rising column induces a hydrodynamic effect not addressed to date-a 'volcanic mesocyclone'. This volcanic mesocyclone sets the entire plume rotating about its axis, as confirmed by an unprecedented analysis of satellite images from the 1991 eruption of Mount Pinatubo. Destabilized by the rotation, the umbrella loses axial symmetry and becomes lobate in plan view, in accord with satellite records of recent eruptions on Mounts Pinatubo, Manam, Reventador, Okmok, Chaiten and Ruang. The volcanic mesocyclone spawns waterspouts or dust devils, as seen in numerous eruptions, and groups the electric charges about the plume to form the 'lightning sheath' that was so prominent in the recent eruption of Mount Chaiten. The concept of a volcanic mesocyclone provides a unified explanation for a disparate set of poorly understood phenomena in strong volcanic plumes.
Edmonds, Y.; Strow, L. L.; Carn, S.; Machado, S. D.; Hannon, S.
Since its launch on EOS/Aqua in May 2002, the Atmospheric Infrared Sounder (AIRS) has successfully detected SO2 and ash clouds emitted during a number of volcanic eruptions. Detection of SO2 is achieved using the strong infrared absorption band of the gas centered around 7.3 μ m. For upper tropospheric volcanic clouds, preliminary AIRS SO2 retrievals performed using a version of the AIRS radiative transfer algorithm that includes variable SO2 indicate good agreement with SO2 amounts detected by the ultraviolet Total Ozone Mapping Spectrometer (TOMS) where coincident data are available. However, the higher spatial, spectral and temporal resolution of AIRS provides much improved coverage of volcanic emissions at lower altitudes, such as the October 2002 eruption of Mt.Etna (Italy). AIRS retrievals of SO2 and ash optical depths and effective particle radii in volcanic clouds from several eruptions will be presented, including Etna, Ruang (Indonesia, September 2002), Reventador (Ecuador, November 2002), Anatahan (Mariana Islands, May 2003) and Soufriere Hills (Montserrat, July 2003). These examples demonstrate the potential of AIRS data to improve measurements of volcanic SO2 and ash loading following eruptions, and to refine our understanding of volcanic cloud composition,structure and evolution.
Bebbington, M. S.; Marzocchi, W.
Many accounts, anecdotal and statistical, have noted a causal effect on volcanic eruptions from large, not too distant, earthquakes. Physical mechanisms have been proposed that explain how small static stress changes, or larger transient dynamic stress changes, can have observable effects on a volcano. While only ˜0.4% of eruptions appear to be directly triggered within a few days of an earthquake, these physical mechanisms also imply the possibility of delayed triggering. In the few regional studies conducted, data issues (selection bias and scarcity, inhomogeneity, and cleaning of data) have tended to obscure any clear signal. Using a perturbation technique, we first show that the Indonesian volcanic region possesses no statistically significant coupling for the region as a whole. We then augment a number of point process models for eruption onsets by a time-, distance-, and earthquake magnitude-dependent triggering term and apply this to the individual volcanoes. This method weighs both positive and negative (i.e., absence of eruptions following an earthquake) evidence of triggering. Of 35 volcanoes with at least three eruptions in the study region, seven (Marapi, Talang, Krakatau, Slamet, Ebulobo, Lewotobi, and Ruang) show statistical evidence of triggering over varying temporal and spatial scales, but only after the internal state of the volcano is accounted for. This confirms that triggering is fundamentally a property of the internal magma plumbing of the volcano in question and that any earthquake can potentially "advance the clock" toward a future eruption. This is further supported by the absence of any dependence on triggering of the eruption size.
Jaffe, Lillie A.; Hilton, David R.; Fischer, Tobias P.; Hartono, Udi
The Sangihe Arc is presently colliding with the Halmahera Arc in northeastern Indonesia, forming the world's only extant example of an arc-arc collision zone. We report the first helium and carbon isotopic and relative abundance data from the Sangihe Arc volcanoes as a means to trace magma origins in this complicated tectonic region. Results of this study define a north-south trend in 3He/4He, CO2/3He, and δ13C, suggesting that there are variations in primary magma source characteristics along the strike of the arc. The northernmost volcanoes (Awu and Karangetang) have higher CO2/3He and δ13C (up to 179 × 109 and -0.4‰, respectively) and lower 3He/4He (˜5.4 RA) than the southernmost volcanoes (Ruang, Lokon, and Mahawu). Resolving the arc CO2 into component structures (mantle-derived, plus slab-derived organic and carbonate CO2), the northern volcanoes contain an unusually high (>90%) contribution of CO2 derived from isotopically heavy carbonate associated with the subducting slab (sediment and altered oceanic basement). Furthermore, the overall slab contribution (CO2 of carbonate and organic origin) relative to carbon of mantle wedge origin is significantly enhanced in the northern segment of the arc. These observations may be caused by greater volumes of sediment subduction in the northern arc, along-strike variability in subducted sediment composition, or enhanced slab-derived fluid/melt production resulting from the superheating of the slab as collision progresses southward.
Jaffe, L. A.; Hilton, D. R.; Fischer, T. P.; Hartono, U.
The Sangihe and Halmahera arcs in northeastern Indonesia are presently colliding, forming the world's only extant example of an arc-arc collision. We report the first helium and carbon isotopic and relative abundance data from the Sangihe Arc volcanoes as a means to trace magma origins in this complicated tectonic region. Gas chemistry and N-isotopes from the same localities are reported in a companion paper (Clor et al, this volume). There is a distinct regional pattern in He and CO2 variations along the north-south strike of the Sangihe Arc. The two northernmost volcanoes (Awu and Karangetang) have 3He/4He <= 6.4RA (where RA = air 3He/4He), CO2/3He >= 30x109, and δ13C >= -2.0‰ . In contrast, the southern volcanoes along the arc (Ruang, Lokon, Mahawu) have 3He/4He >= 7.0RA, CO2/3He < 7x109 and δ13C < -3.0‰ . The southern volcanoes, therefore, sample volatiles more typical of island arc volcanoes. Resolving the CO2 into component structures (mantle-derived, plus slab-derived organic and limestone CO2 - following the approach of Sano and Marty, Chem. Geol., 1995), the northern volcanoes contain higher than average slab-derived limestone contributions. For example, limestone-derived CO2 makes up > 90% of the total CO2 at Karangetang and ~98% at Awu. These values compare with an average limestone contribution of ~65% in the southern Sangihe arc and ~73% in other arcs worldwide. We are investigating possible reasons for the enhanced limestone contributions in the northern Sangihe arc. The sedimentary mélange wedge is thickest in the north (up to 15km) - where the arcs initially collided. The greater availability of sediment may result in a greater input of subducted sediment, thereby providing enhanced dilution of mantle wedge C inputs. Alternatively, subducted sediments may be more carbonate-rich in the northern segment of the arc. This may reflect obduction of shallow, organic-bearing sediments onto the over-riding plate, leaving only pelagic carbonates to
Clor, L. E.; Fischer, T. P.; Hilton, D. R.; Sharp, Z.; Hartono, U.
We report the first data on volatile emissions from the Sangihe Volcanic Arc to trace sediment subduction. The Sangihe Arc is part of an unusual tectonic setting where the Molucca Sea Plate subducts beneath both the Sangihe and Halmahera Arcs, resulting in oblique arc-arc collision. The northern parts of Sangihe and Halmahera are fused, while the south has not yet collided. Collision has resulted in sediment obduction onto the facing arcs, decoupling it from the oceanic plate below. To study the geochemical effects of collision, we collected gases at eight locations along Sangihe Arc at fumaroles and hot springs. Our results complement CO2-He systematics of the same samples (Jaffe et al., this volume). Gas samples were analyzed for major volatiles and N isotopes. Typical N2/He for subduction zones are 1000-25,000, while MORB and OIB are lower (10-100) due to the lack of sediment-derived N input. Most Sangihe samples have N2/He that deviate from the subduction signature (330-2825). The N isotopic (δ15N) value of air is 0‰ by definition, -3 to -5‰ in the upper mantle, and +7‰ in marine sediments. δ15N values for Sangihe samples range from -7 to +2‰ . Variations in N2/He ratios and δ15N data (tracers of hemipelagic sediment) correlate with latitude, with values decreasing to the north suggesting that subduction of hemipelagic sediment is less significant in the north than the south. The N2-He systematics suggest that arc-arc collision, more advanced in the north (where N2/He=537 and δ15N=-7‰ at Ruang Volcano), has caused the sediment package to become less coupled to the underlying ocean crust. The higher values in the south (N2/He=1977 and δ15N=+2‰ at Ambang Volcano) suggest that sediment is still subducting there, as the collision is less developed. Alternatively, sediment composition may vary along strike of the arc, with hemipelagic and carbonate-rich sediments subducted in the south and north, respectively.
Pentaris, Fragkiskos P.; Papadopoulos, Ilias
of Education of Greece and the European Union in the framework of the project entitled «Interdisciplinary Multi-Scale Research of Earthquake Physics and Seismotectonics at the front of the Hellenic Arc (IMPACT-ARC) ». References  F. P. Pentaris, J. Stonham, and J. P. Makris, "A review of the state-of-the-art of wireless SHM systems and an experimental set-up towards an improved design," presented at the EUROCON, 2013 IEEE, Zagreb, 2013.  R. Ditommaso, M. Mucciarelli, S. Parolai, and M. Picozzi, "Monitoring the structural dynamic response of a masonry tower: Comparing classical and time-frequency analyses," Bulletin of Earthquake Engineering, vol. 10, pp. 1221-1235, 2012.  Sungkono, D. D. Warnana, Triwulan, and W. Utama, "Evaluation of Buildings Strength from Microtremor Analyses " International Journal of Civil & Environmental Engineering IJCEE-IJENS, vol. 11, 2011.  L.-L. Hong and W.-L. Hwang, "Empirical formula for fundamental vibration periods of reinforced concrete buildings in Taiwan," Earthquake Engineering & Structural Dynamics, vol. 29, pp. 327-337, 2000.