An important measure of eruptive strength is the Volcanic Explosivity Index an order-of-magnitude scale, ranging from 0 to 8, that often correlates to eruptive types

Eruption mechanisms
Volcanic eruptions arise through three main mechanisms:
Gas release under decompression, causing magmatic eruptions
Ejection of entrained particles during steam eruptions, causing phreatic eruptions
Thermal contraction from chilling on contact with water, causing phreatomagmatic eruptionsThere are two types of eruptions in terms of activity, explosive eruptions and effusive eruptions. Explosive eruptions are characterized by gas-driven explosions that propels magma and tephra. Effusive eruptions, meanwhile, are characterized by the outpouring of lava without significant explosive eruption.Volcanic eruptions vary widely in strength. On the one extreme there are effusive Hawaiian eruptions, which are characterized by lava fountains and fluid lava flows, which are typically not very dangerous. On the other extreme, Plinian eruptions are large, violent, and highly dangerous explosive events. Volcanoes are not bound to one eruptive style, and frequently display many different types, both passive and explosive, even in the span of a single eruptive cycle. Volcanoes do not always erupt vertically from a single crater near their peak, either. Some volcanoes exhibit lateral and Fissure eruptions. Notably, many Hawaiian eruptions start from rift zones. Scientists believed that pulses of magma mixed together in the magma chamber before climbing upward—a process estimated to take several thousands of years. However, Columbia University volcanologists found that the eruption of Costa Ricas Irazú Volcano in 1963 was likely triggered by magma that took a nonstop route from the mantle over just a few months.
Similarly, increasing numbers of Chinese were also traveling to India to purchase sofosbuvir, which had not yet been approved for sale in China by the countrys State Food and Drug Administration (SFDA). Research
Combinations of sofosbuvir with NS5A inhibitors, such as daclatasvir, ledipasvir or velpatasvir, have shown sustained virological response rates of up to 100% in people infected with HCV. Most studies indicate that the efficacy rate is between 94% and 97%; much higher than previous treatment options. That treatments could be conducted at very low costs was demonstrated by Hill and coworkers who presented data on 1,160 patients who used generic versions of solfosbuvir, ledipasvir, plus daclatasvir from suppliers in India, Egypt, China and other countries and reported over 90% success at costs of about $50 per therapy.Sofosbuvir has also been tested against other viruses such as the Zika virus and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). See also
AT-527—a similar drug developed for the treatment of SARS-CoV-2
Tenofovir alafenamide—a nucleotide reverse-transcriptase inhibitor that uses similar phosphoramidate prodrug technology
Remdesivir—a nucleotide analogue RNA polymerase inhibitor originally intended to treat hepatitis C that uses similar phosphoramidate prodrug technology and displays very similar PK. References
Further reading
Dean L (2017). "Sofosbuvir Therapy and IFNL4 Genotype". In Pratt VM, McLeod HL, Rubinstein WS,  et al. (eds.). Medical Genetics Summaries. National Center for Biotechnology Information (NCBI). PMID 28520377. Bookshelf ID: NBK409960. External links
"Sofosbuvir". Drug Information Portal. U.S. National Library of Medicine.