A Global Historical Megatsunami Catalog (GHMCat) is presented, including all the events documented to date. The oldest event is from 1674 the Santorini event, ~3600 BP, is considered a particular case, and the most recent is from 2020. Although there is no formal definition of the term megatsunami, it is usually associated to the maximum height or runup reached by the waves when hitting the coast. Here we adopt this criterion and define a megatsunami when the wave reaches a height of 40 m or more. The catalog is initially based on tsunamis that meet this condition from the two existing Global Historical Tsunami Databases (GHTDs). Then, each of the events have been researched for its available references including earliest in order to verify the data, mainly on the maximum height of the waves and their causes. After a comprehensive review of published or on-line literature on historical tsunamis, including regional and local catalogs, papers, books, studies, reports and other available references, some of the oldest events have been ruled out. On the other hand, the literature review has also led to include in the catalog some new megatsunamis not included in the GHTDs. The global catalog contains 37 events from 1674 to 2023, 11 of which are either not included in the GHTDs or included with (erroneous) wave heights <40 m. All of them are described and characterized as far as can be gathered within the limitations of the scope of a global catalog and the available information on each historical case. The analysis of recorded historical megatsunamis shows that virtually all have been originated by large landslides, most of them subaerial landslides, with an unusual frequency of events in certain glaciated areas of Alaska and Norway, mainly in the first decades of the 20th century. In contrast, it is worth noting the small number of megatsunamis caused by submarine landslides or associated with volcanic explosions.

The overall seismicity of Pakistan from 24 B.C to 2020 is analysed in terms of its multifractal behaviour. Seismic events of magnitude ML=3.0 and above are spatially clustered into four distinct groups, each one corresponding to a different region of high seismic activity. The Multifractal Detrended Fluctuation Analysis (MFDA) method applied on each cluster reveals pronounced inter-cluster heterogeneity in terms of the resulting generalised Hurst exponent and fractality spectrum, possibly due to the particular tectonic characteristics of the regions under investigation. Additional results on the variability of the Gutenberg–Richter b‐value across the defined clusters further corroborate the uniqueness of the seismic profile of each region.

A high-resolution catalog for the 2014 Ms6.5 Ludian aftershocks was constructed based on the deep learning phase-picking model (CERP) and the seismic-phase association technology (PALM). A specific training strategy, which combines the advantages of the conventional short-long window average energy ratio algorithm (STA/LTA) and AI algorithm, is employed to retrain the CERP model. The P & S phases were accurately detected and picked on continuous seismic waveforms by the retained AI model. Hypoinverse and HypoDD were utilized for precise location of 3286 events. Compared to the previous results, our new catalog exhibits superior performances in terms of location accuracy and the number of aftershock events, thereby enabling a more de-tailed depiction of the deep-seated tectonic features. According to the distribution of aftershocks, it can be inferred that, (1) the seismogenic fault of Ludian earthquake is the NW-trending Baogunao-Xiaohe Fault. (2) the Ludian aftershocks interconnected the discontinuous NW-trending Baogunao-Xiaohe Fault, and intersected with the Zhaotong-Ludian Fault. (3) It suggests that the NE-trending Zhaotong-Ludian Fault may have been intersected by the NW-trending Baogunao -Xiaohe Fault, indicating that the Baogunao-Xiaohe Fault is likely a rela-tively young Neogene fault.

The possibility of the life origin in the stellar systems, located at a distance of ~ 200 pc from the solar system, was investigated. The stars, in the spectrums of which C (carbon), O (oxygen), N (nitrogen), and P (phosphorus) are found, are called DNA–stars. Based on stellar abundances a new method for searching for habitable exoplanets has been developed and a list of 48 DNA–stars in the solar neighborhood, on which life is possible, has been defined. The quota of DNA–stars is equal 1.3% of the total amount of Hypatia Stellar Catalog. Only three DNA–stars out of selected 48 stars belong to the spectral class as our Sun (G2V). The closest to the solar system is the DNA-star with the number HIP 15510, which belongs to the G8V class and is 6 pc away from the solar system. Nine DNA--stars, which have the highest chemical similarity with solar spectrum, were identified. It is identified that one of these nine stars, HIP 24681, has six planets.

A concept of ensemble averaged stellar reactors is developed to study the dynamics of processes occurring in stars, allocated in the ~ 200 pc solar neighborhood. According to the effective temperature value, four stellar classes are identified, for which the correlation coefficients and standard deviation are counted. The theory of the buoyancy terrestrial elements is generalized to stellar systems. It was suggested that stars are over-heated due to the shift parameters of the nuclear processes occurring inside the stars, which leads to the synthesis of transuranium elements until the achievement of a critical nuclear mass and star explosion. The heavy transuranium elements sink downward and are concentrated in the stellar depth layers. The physical explanation of the existence of the critical Chandrasekhar star limit has been offered. Based on the spatial analysis of overheated stars, it was suggested that the withdrawal of the stellar reactor from the equilibrium state is a consequence of extragalactic compression inside the galaxy arm due to the arm spirality (not to be confused with the spirality of the galaxy itself).