Impact cratering has been an important process in the solar system. The cratering event is generally accompanied by faulting in adjacent terrain. Impact-induced faults are nearly ubiquitous over large areas on the terrestrial planets. The suggestion is made that these fault systems, particularly those associated with the largest impact features are preferred sites for later deformation in response to lithospheric stresses generated by other processes. The evidence is a perceived clustering of orientations of tectonic features either radial or concentric to the crater or basin in question. An opportunity exists to test this suggestion more directly on Earth. The terrestrial continents contain more than 100 known or probable impact craters, with associated geological structures mapped to varying levels of detail. Prime facie evidence for reactivation of crater-induced faults would be the occurrence of earthquakes on these faults in response to the intraplate stress field. Either an alignment of epicenters with mapped fault traces or fault plane solutions indicating slip on a plane approximately coincident with that inferred for a crater-induced fault would be sufficient to demonstrate such an association.
The Greenhouse gases Observing SATellite (GOSAT) is designed to measure the concentration of major greenhouse gases from space. GOSAT carry the Fourier-Transform Spectrometer, which have three shortwave infrared (SWIR) bands and one thermal infrared (TIR) band. The SWIR bands correspond to the O2A band (0.76 mm), weak-CO2 (1.6 mm) and strong-CO2 (2.0 mm). The SWIR bands observe the backscattered sunlight from surface and retrieve the column-averaged dry air mole fraction of carbon dioxide and methane. The 0.76 mm band can also detect the solar-induced chlorophyll fluorescence (SIF) using high spectral-resolution spectra in O2A band and solar absorption feature (Fraunhofer lines). GOSAT have operated more than 8 years and targeted various kinds of land-cover area (forest, grass, desert, etc.). The long term CO2 and SIF data set potential to address the rate of CO2 uptake through plant photosynthesis. In this work, we evaluated a trend and seasonal fluctuation components of CO2 and SIF using the liner and trigonometric functions fitting. We analyzed the amplitude and phase of the CO2 and SIF seasonal variation and anomalies over selected sites. Spatial distribution from target observation dataset which consist of 16 point per site using an agile pointing system over megacity is presented together with wind data. The data is available from the GOSAT trend viewer at _monitor/.
Recent studies have utilized coarse spatial and temporal resolution remotely sensed solar-induced fluorescence (SIF) for modeling terrestrial gross primary productivity (GPP) at regional scales. Although these studies have demonstrated the potential of SIF, there have been concerns about the ecophysiological basis of the relationship between SIF and GPP in different environmental conditions. Launched in 2014, the Orbiting Carbon Observatory-2 (OCO-2) has enabled fine-scale (1.3 by 2.5 km) retrievals of SIF that are comparable with measurements recorded at eddy covariance towers. In this study, we examine the effect of environmental conditions on the relationship of OCO-2 SIF with tower GPP over the course of a growing season at a well-characterized natural grassland site. Combining OCO-2 SIF and eddy covariance tower data with a canopy radiative transfer and an ecosystem model, we also assess the potential of OCO-2 SIF to constrain the estimates of Vcmax, one of the most important parameters in ecosystem models. Based on the results, we suggest that although environmental conditions play a role in determining the nature of relationship between SIF and GPP, overall, the linear relationship is more robust at ecosystem scale than the theory based on leaf-level processes might suggest. Our study also shows that the ability of SIF to constrain Vcmax is weak at the selected site. 2b1af7f3a8