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Rajesh Janardanan, Shamil Maksyutov, Aki Tsuruta, Fenjuan Wang, Yogesh K. Tiwari, Vinu Valsala, Akihiko Ito, Yukio Yoshida, Johannes W. Kaiser, Greet Janssens-Maenhout, Mikhail Arshinov, Motoki Sasakawa, Yasunori Tohjima, Douglas E. J. Worthy, Edward J. Dlugokencky, Michel Ramonet, Jgor Arduini, Jost V. Lavric, Salvatore Piacentino, Paul B. Krummel, Ray L. Langenfelds, Ivan Mammarella, Tsuneo Matsunaga. (2020). Country-Scale Analysis of Methane Emissions with a High-Resolution Inverse Model Using GOSAT and Surface Observations (Vol. 12).
Keywords: anthropogenic GOSAT inverse model methane emission UNFCCC wetland
Programme: 416
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Roman Sulzbach, Hartmut Wziontek, Michael Hart-Davis, Henryk Dobslaw, Hans-Georg Scherneck, Michel Van Camp, Ove Christian Dahl Omang, Ezequiel D. Antokoletz, Christian Voigt, Denise Dettmering, Maik Thomas. (2022). Modeling gravimetric signatures of third-degree ocean tides and their detection in superconducting gravimeter records (Vol. 96).
Keywords: Degree-3 tides Superconducting gravimetry Tidal analysis Tidal modeling Tide gauge data
Programme: 688
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Bruhwiler L M P, Michalak A M, Tans P P. (2011). Biogeosciences, 8(5), 1309–1331.
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. (2018). Characterizing Atmospheric Transport Pathways to Antarctica and the Remote Southern Ocean Using Radon-222 (Vol. 6). Bachelor's thesis, , .
Keywords: Antarctica atmospheric transport MBL Mercury Ozone Radon Southern Ocean Troposphere
Programme: 1028
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J. Mouginot, E. Rignot, Y. Gim, D. Kirchner, E. Le Meur. (2014). Low-frequency radar sounding of ice in East Antarctica and southern Greenland (Vol. 55).
Keywords: Antarctic glaciology ground-penetrating radar radio-echo sounding remote sensing
Programme: 1053
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Tocheport, A.; Rivera, L.; Chevrot, S. (2007). A systematic study of source time functions and moment tensors of intermediate and deep earthquakes. J. Geophys. Res., 112.
Keywords: Deep earthquakes; body waves inversion; source parameters; 7203 Seismology: Body waves; 7215 Seismology: Earthquake source observations; 7209 Seismology: Earthquake dynamics; 8120 Tectonophysics: Dynamics of lithosphere and mantle: general
Programme: 133
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Yagi Yuji, Nakao Atsushi, Kasahara Amato, . (2012). Smooth and rapid slip near the Japan Trench during the 2011 Tohoku-oki earthquake revealed by a hybrid back-projection method
. Earth Planet. Sci. Lett., 355-356, 94–101.
Abstract: We developed a new back-projection method that uses teleseismic P-waveforms to integrate the direct P-phase with reflected phases from structural discontinuities near the source and used it to estimate the spatiotemporal distribution of the seismic energy release of the 2011 Tohoku-oki earthquake. We projected a normalized cross-correlation of observed waveforms with corresponding Green's functions onto the seismic source region to obtain a high-resolution image of the seismic energy release. Applying this method to teleseismic P-waveform data of the 2011 Tohoku-oki earthquake, we obtained spatiotemporal distributions of seismic energy release for two frequency bands, a low-frequency dataset and a high-frequency dataset. We showed that the energy radiated in the dip direction was strongly frequency dependent. The area of major high-frequency seismic radiation extended only downdip from the hypocenter, whereas the area of major low-frequency seismic radiation propagated both downdip and updip from the hypocenter. We detected a large release of seismic energy near the Japan Trench in the area of maximum slip, which was also the source area of the gigantic tsunami, when we used only the low-frequency dataset. The timing of this large seismic energy release corresponded to an episode of smooth and rapid slip near the Japan Trench, and reflects the strong dependence of the seismic energy distribution obtained on the frequency band of the input waveform dataset. The episode of smooth and rapid slip may have been the trigger for a release of roughly all of the accumulated elastic strain in the seismic source region of the 2011 Tohoku-oki earthquake.
Keywords: 2011 Tohoku-oki earthquake, back-projection, seismic source process, smooth and rapid slip near trench,
Programme: 133
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L A Ermert, K Sager, T Nissen-Meyer, A Fichtner. (2021). Multifrequency inversion of global ambient seismic sources (Vol. 225).
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Jiuxun Yin, Marine A. Denolle, Huajian Yao. (2018). Spatial and Temporal Evolution of Earthquake Dynamics: Case Study of the Mw 8.3 Illapel Earthquake, Chile (Vol. 123).
Abstract: We develop a methodology that combines compressive sensing backprojection (CS-BP) and source spectral analysis of teleseismic P waves to provide metrics relevant to earthquake dynamics of large events. We improve the CS-BP method by an autoadaptive source grid refinement as well as a reference source adjustment technique to gain better spatial and temporal resolution of the locations of the radiated bursts. We also use a two-step source spectral analysis based on (i) simple theoretical Green's functions that include depth phases and water reverberations and on (ii) empirical P wave Green's functions. Furthermore, we propose a source spectrogram methodology that provides the temporal evolution of dynamic parameters such as radiated energy and falloff rates. Bridging backprojection and spectrogram analysis provides a spatial and temporal evolution of these dynamic source parameters. We apply our technique to the recent 2015 Mw 8.3 megathrust Illapel earthquake (Chile). The results from both techniques are consistent and reveal a depth-varying seismic radiation that is also found in other megathrust earthquakes. The low-frequency content of the seismic radiation is located in the shallow part of the megathrust, propagating unilaterally from the hypocenter toward the trench while most of the high-frequency content comes from the downdip part of the fault. Interpretation of multiple rupture stages in the radiation is also supported by the temporal variations of radiated energy and falloff rates. Finally, we discuss the possible mechanisms, either from prestress, fault geometry, and/or frictional properties to explain our observables. Our methodology is an attempt to bridge kinematic observations with earthquake dynamics.
Keywords: backprojection earthquake dynamics Illapel Earthquake radiated energy
Programme: 133
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. (2017). Monitoring photo-oxidative and salinity-induced bacterial stress in the Canadian Arctic using specific lipid tracers (Vol. 194).
Abstract: We determined, and compared, the abiotic stress state of algae and their attached bacterial communities following their release into the water column during the Arctic sea ice melt season using specific lipid markers that are characteristic of type II photo-oxidation processes, together with those associated with cis-trans isomerase and 10S-DOX-like lipoxygenase activity, which are indicative of salinity stress. More specifically, parent lipids and some of their oxidation products were quantified in sinking particles (from sediment traps) collected from the Beaufort Sea, Resolute Passage and the Davis Strait (Canadian Arctic) in 2009, 2012 and 2015, respectively. Our data show that salinity- and light-induced bacterial stress processes are temporally decoupled, with the former occurring at the beginning of ice melting and the latter observed during the final stages of ice melt and in subsequent open waters. The salinity-induced bacterial stress seen during the early stages of ice melting contrasts the healthy state of sea ice algae under the same hypersaline conditions. As sea ice melt progresses, brine channels become hyposaline, thus reducing the bacterial salinity stress, while ice algae become susceptible to photodegradation by singlet oxygen (1O2), despite relatively low temperatures and irradiance. However, the presence of high amounts of extracellular polymeric substances (EPS) encapsulating the algae likely prevents the diffusion of 1O2 to the attached bacteria. Photo-oxidative stress is enhanced further in open waters due to the low amounts of EPS. The lower amounts of active bacteria in the Arctic compared to temperate or tropical regions is thus attributed to the combined action of efficient salinity stress in spring and photo-oxidative stress in summer. Outcomes from this study also imply that surface sediments from the Canadian Arctic contain relatively high quantities of sea ice-derived organic matter that has undergone a strong degree of salinity-induced stress.
Keywords: 10-DOX-like lipoxygenase Arctic environment Bacteria EPS Ice algae isomerase Light stress Lipid biomarkers Phytoplankton Salinity stress
Programme: 1164
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