Seafloor geophysical instrumentation is challenging to deploy and maintain but critical for studying submarine earthquakes and Earth’s interior. Emerging fiber-optic sensing technologies that can leverage submarine telecommunication cables present an opportunity to fill the data gap. We successfully sensed seismic and water waves over a 10,000-kilometer-long submarine cable connecting Los Angeles, California, and Valparaiso, Chile, by monitoring the polarization of regular optical telecommunication channels. We detected multiple moderate-to-large earthquakes along the cable in the 10-millihertz to 5-hertz band. We also recorded pressure signals from ocean swells in the primary microseism band, implying the potential for tsunami sensing. Our method, because it does not require specialized equipment, laser sources, or dedicated fibers, is highly scalable for converting global submarine cables into continuous real-time earthquake and tsunami observatories.

The nanostructure of three bioactive materials, two sol-gel glasses in the SiO 2 -CaO and SiO 2 -CaO-P 2 O 5 systems and a SiO 2 -CaO-poly(dimethylsiloxane) organic-inorganic hybrid, has been studied for the first time by high-resolution transmission electron microscopy. The nanostructural characterization indicates that the addition of P 2 O 5 to the glass leads to crystallization of a silicon-doped calcium phosphate, while in the materials without any phosphorus contentsbinary glass and hybridscalcium is located in an amorphous silica network. The different rates of positive bioactive response of both glasses (with and without phosphorus) are strongly correlated with their nanostructure since the distances between [SiO 4 4-] tetrahedra decrease when calcium is not present in the vitreous network and phosphorus bonds to calcium to form a silicon-doped calcium phosphate.

Anatase TiO 2 nanoparticles doped with Al or Fe have been synthesized via a modified Pechini method which allows us to reach high control in size and composition. Microstructural analysis confirms the good crystallinity of the doped anatase nanoparticles with average sizes around 5 nm and dopant cationic concentrations up to 30%. The anatase to rutile transition (ART) has been thermally driven and analyzed as a function of the doping. Thermo-diffraction measurements indicate that the phase transition can be either promoted or inhibited by Fe or Al doping, respectively. The influence of Al and Fe doping on the phase transition has been discussed by means of Raman spectroscopy, photoluminescence and X-ray photoelectron spectroscopy, with special attention paid to the role played by Ti 3+ at the surface. The anatase phase has been stabilized up to temperatures above 900 C by appropriate Al doping.

Coherent radiators imaged by backprojections (BP) are commonly interpreted as part of the rupture process. Nevertheless, artifacts introduced by structure related phases are rarely discriminated from the rupture process. In this study, we use a calibration event to discriminate between rupture and structure effects. We reexamine the waveforms and BP images of the 2012 Mw 7.2 Indian Ocean earthquake and a calibration event (Mw 6.2). The P wave codas of both events present similar shape with characteristic period of approximately 10 s, which are backprojected as coherent radiators near the trench. S wave BP does not image energy radiation near the trench. We interpret those coda waves as localized water reverberation phases excited near the trench. We perform a 2‐D waveform modeling using realistic bathymetry model and find that the steep near‐trench bathymetry traps the acoustic water waves forming localized reverberation phases. These waves can be imaged as coherent near‐trench radiators with similar features as that in the observations. We present a set of methodologies to discriminate between the rupture and propagation effects in BP images, which can serve as a criterion of subevent identification.

The deciduous tropical dry forest at Chamela (Jalisco, Mexico) occurs in a seasonal climate with eight rainless (November through June) and four wet months (700 mm annual precipitation). The forest reaches a mean height of 10 m. Tree density in the research area was 4700 trees per ha with a basal area at breast height of 23 m 2 per ha. The above-and below-ground biomass of trees, shrubs, and lianas was 73.6 Mg ha-and 31 Mg ha -1, respectively. A root:shoot biomass ratio of 0.42 was calculated. Nearly two thirds of all roots occur in the 0-20 cm soil layer and 29% of all roots have a diameter of less than 5 mm.