Statistical analysis of environmental parameters on the occurrences of tropical cyclones and earthquakes: an example from West North Pacific region

• Published in: Marine geophysical researches 2022-12, Vol.43 (4), p.44, Article 44
• Main Author: Pandey, Ravi Shankar
• Format: Article
• Language: English
• Subjects: Boundaries; Cyclogenesis; Cyclones; Earth and Environmental Science; Earth Sciences; Earthquakes; Environmental factors; Environmental parameters; Geographical information systems; Geophysics/Geodesy; Hurricanes; Lithosphere; Long wave radiation; Oceanography; Offshore Engineering; Original Research Paper; Parameters; Radiation; Relative humidity; Relative vorticity; Sea level; Sea level pressure; Sea surface; Sea surface temperature; Seismic activity; Seismicity; Statistical analysis; Statistical methods; Subduction; Subduction zones; Summer; Surface temperature; Tropical cyclones; Troposphere; Tropospheric winds; Vertical shear; Vertical velocities; Vertical wind shear; Winds
• ISSN: 0025-3235; 1573-0581
• DOI: 10.1007/s11001-022-09505-w

The nature of earthquake events and atmospheric factors’ response to the tropical cyclones (TCs) frequency during the boreal summer (June–July–August: JJA) season in the West North Pacific (WNP) is investigated using a 45-year (1977–2021) monthly dataset. The WNP is the most cyclonically active basin on the globe and boreal summer alone accounts for its 42% of share. The WNP region encompasses the subduction zones between the Pacific and Philippine Sea plates, where 32% of boreal summer TCs cross these plates’ boundaries. Here I conduct statistical and GIS analyses of many environmental parameters on the occurrence of TCs in the WNP and seismicity along the plates’ boundaries. Years with frequent TCs in the WNP correlate with statistically significantly high seismicity in the lithosphere, assuming a 75 km (correl: 0.75) and a 120 km (correl: 0.75) lithospheres, respectively. TCs do not need to cross the plates’ boundaries to increase the seismicity (correl: 0.47 and 0.43 for 75 km and 120 km lithosphere, respectively), possibly due to the large spatial areas affected by each TC. Among the environmental parameters investigated, relative vorticity is strongly linked with TC frequency in the WNP in boreal summer showing a maximum percentage of variation during both extremely high and low TC years. Higher-level tropospheric winds (200 hPa) and vertical shear are found more dominant in extremely high-TC years while middle level tropospheric winds (850 hPa) and vertical velocity (omega) are found more commanding in extremely low-TC years. Other factors like sea surface temperature, relative humidity, outgoing longwave radiation, sea level pressure, etc. are also found mutually connected through the environmental and dynamical processes and as a result influence cyclogenesis. Results from this work suggest that few environmental parameters may dominantly control the extreme cyclogenesis, which then influences seismicity along submerged plates’ boundaries. Having the earthquakes and TCs as two major destruction casing natural hazards in the region, the presented results are very valuable.