Beschreibung: Several efforts have been made recently to develop new tools based on ionospheric indices derived from the Global Navigation Satellite System (GNSS) data to improve our knowledge of the effects of Magnetic Storm and Equatorial Plasma Bubbles (EPB) over the ionosphere at equatorial and low latitude regions in the American sector. Concurrently, the Ksa (K for South America), a local geomagnetic index have been developed to overcome the need for observatories in the South American sector providing data for binding the “planetary” Kp index, widely used as a global response to space weather disturbances. In the present work, we present and discuss results from studies recently published and under preparation related to the use of these indices. Concerning the ionospheric indices, we have primarily focused on studies about the detection (or detectability), and measurement of parameters related to EPBs (latitudinal extension and velocity). Finally, we compare differences in the time evolution of the regional versus the global magnetic indices.

Beschreibung: This work analyzes the worldwide development of Sporadic E (Es) layers in different regions during a High-Speed Solar Wind Stream (HSS) event on March 18, 2018. We used Digisonde data from auroral, equatorial, and low-middle latitude stations as the primary source for the analysis. We also examined a set of data from selected geomagnetic quiet days to compare the Es layer behavior in such regions. The preliminary results agreed with the understanding that the wind shear mechanism is the principal agent causing the Es layer behavior around the globe, except for the auroral region. Magnetometer and Total Electron Content (TEC) data showed that an undershielding electric field could also influence the Es layer formation over equatorial regions. Further, we observed auroral-type Es layer (Esa) occurrence in the South American Magnetic Anomaly (SAMA). The particle precipitation dynamics between the auroral site and SAMA region have different ways of acting in the Esa layer formation. Finally, our analysis provided a deep understanding of the Es layer behavior in different latitudes during a specific space weather event.

Beschreibung: This report documents the drilling operations of the Early Jurassic Earth System and Timescale scientific drilling project (JET, ICDP Project: 5065). The wells 5065_1_A, 5065_1_B, 5065_1_A were drilled in 2019-2021 with the support of the International Continental Scientific Drilling Program (ICDP) and the UK Natural Environment Research Council (NERC). Alternatively, the site is known as Prees 2 (Holes A – C). Prees 1 was a nearby hydrocarbon exploration well drilled by Trend Petroleum in 1972–1973. The project aims to construct a fully integrated and astronomically calibrated timescale for the Early Jurassic, a time in Earth history during which important physical, chemical, and biological elements of the modern Earth system were initiated. The JET drilling campaign supplements the earlier Llanbedr (Mochras Farm) borehole (1967 – 1969) in NW Wales – usually known as Mo-chras – which recovered a 1.3 km thick succession comprising the Rhaetian (Upper Triassic), Hettangian, Sinemurian, Pliensbachian and Toarcian (Lower Jurassic) stages (Woodland, 1971; Hesselbo et al., 2013). Using the combined framework of Prees and Mochras, internal and ex-ternal forcing factors on the Earth system will be documented and quantified for major palaeo-environmental events, such as the Late Triassic mass extinction and the Early Toarcian Oceanic Anoxic Event, and for the more stable ‘background’ state.

Beschreibung: The island of São Miguel is among the most seismically active areas of the Azores archipelago. This work focuses on the most significant recent swarm, which occurred on February 2018. We set up an automated procedure to process continuous full seismic waveform data from local stations to generate high-quality earthquake information on the volcano unrest episode. First, we applied an automated detector software, next we located the detected events and then classified the earthquakes based on their waveform similarity, identifying three families of seismic events. We then extended the catalog by template matching. Finally, we computed moment tensors to investigate the source mechanisms of the largest earthquakes. Our results image the ∼2-week swarm evolution. The activity started with a precursory phase with low rate and low magnitude (ML 〈 2.0) seismicity and the activation of a deeper structure (∼10-15 km). After ∼1 week, a new earthquake family emerged at shallower depths (∼8–12 km) reaching magnitudes up to ML 3.4. Finally, a third slightly shallower family was activated. Moment tensors show mostly normal faulting mechanisms, striking ∼NW-SE, compatible with the orientation of the regional stress field. A surface deformation transient was recorded by geodetic stations, starting with the swarm, and continuing over the following ∼17 months, corresponding to either inflation or extension around the swarm region. The prolonged surface deformation implies a process that was initiated during the swarm and subsequently accommodated mostly aseismically. We interpret the seismicity observed at the early stage of deformation as indicating episodic fluid injection through the crust, related to the local hydrothermal or magmatic systems. We conclude that the Fogo-Congro region continues to be seismo-volcanically active, with both seismic and aseismic deformation observed and requiring close multidisciplinary monitoring. The proposed methology based on the automated analysis of continuous waveform data provides high-quality imaging of the spatio-temporal evolution of seismicity, which can be used elsewhere in the operational monitoring of seismo-volcanic crises to gain insight into the ongoing deformation processes, improve hazard assessment and help in the development of effective mitigation strategies.