The morphological characteristics of Qiongbei maars and their implications for eruption history and volcanic hazards
Maars,the second most common type of volcano found on both land and islands,are prevalent in regions inhabited by approximately 10％of the global population.Consequently,the study of maars and their associated hazards exhibits substantial scientific importance.The numerous Quaternary maars in the northern part of Hainan Island offer a natural research subject.Utilizing satellite imagery,digital elevation models and field measurements,we have determined the morphological characteristics of 11 maars in the northern Hainan region.Our findings classify the maars in the northern Hainan into three primary planar shapes,i.e.,circular,elliptical and triangular.These features exhibit variations in areas(ranging in 0.01～3.42km2),perimeters(ranging in 0.43～6.64km),average diameters(ranging in 128～2128m),depths(ranging in 8～50m),estimated total erupted volume(DRE)of 2.2km3 and juvenile volume(DRE)of 1.7km3,explosion energies spanning from 1.2 × 1013J to 6.4 × 1016J,and energy convention ratio ranging between 1％and 2％.Volcanic activity can be categorized into three distinct periods:the initial period,encompassing Yanghualing,Ruhuangling and Nayouling,spanned from 6.35 to 0.11 thousand years;the subsequent period,which featured Chenyongling,Shiling,Luojingpan,Yudunling and Tongleiling,extended from 1.06 to 0.02 thousand years;and the third(final)phase,characterized by Haoxiuling,Shuangchiling Dongling and Xiling,endured for a brief duration ranging from 16 to 0.3 years.Regional stress in the Shishan-Yongxing area significantly influences the elongation direction of the maars.Based on the lateral migration trajectory,the next eruption is anticipated to occur approximately 100～200m west of Shuangchiling Xiling.Maars exhibit a range of disasters,including earthquakes,ash clouds,ash deposition,base surges,volcanic bomb and block ejection,lahars,volcanic gases and psychological trauma.Eruption scenario modeling indicates that volcanic ash from the northern Qiongbei Volcano will impact northern Hainan,southern Guangdong and Guangxi,southern Taiwan in China,and eastern Vietnam.The extent of influence depends on eruption characteristics and real-time climatic conditions.In summary,we have developed a risk zoning map for volcanic disasters in northern Qiongbei.We recommend conducting comprehensive morphological surveys of volcanoes nationwide and establishing representative case studies to serve as essential references for predicting future volcanic eruptions and preventing volcanic hazards.
MaarMorphologyEruption historyVolcano hazardsMigration of explosionQiongbei area
万方数据
维普
