Impact of historical tsunamis on a sandy coastal barrier: an example from the northern Gargano coast, southern Italy
Impact of historical tsunamis on a sandy coastal barrier: an example from the northern Gargano coast, southern Italy
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历史海啸对沙质海岸屏障的影响：以意大利南部加尔加诺北部海岸为例
DOI：
10.5194/nhess-1-213-2001
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发表时间：
2001
影响因子：
4.6
通讯作者：
P. Sansò
中科院分区：
文献类型：
--
作者：
F. Gianfreda;G. Mastronuzzi;P. Sansò
抽象的。莱西纳海岸屏障的特点是存在三个宽的冲刷扇。它们是由历史上袭击加尔加诺海角（意大利阿普利亚）北方海岸的三次不同的海啸形成的。一个模型，它们的形成。它考虑到了收集到的地貌数据和关于最近海啸对海岸屏障和海滩影响的一些报告。冲覆扇是由海啸波穿过沙丘脊上形成的同震裂缝而产生的，这些裂缝形成了一条狭窄、笔直和相对较深的沟槽，构成了扇喉。此外，每一次海啸事件都很可能造成海岸屏障的严重侵蚀，在沙丘脊上形成侵蚀槽，造成海滩悬崖，并造成海底近海沙洲的营养。海啸过后，海岸屏障开始恢复，形成新的沙丘脊，并关闭了冲刷扇喉。形态学、考古学和放射性数据表明，最古老的事件发生在罗马时代之前，距今2430年。第二次海啸袭击了莱西纳海岸屏障与类似的规模1550年BP;它是由强烈的地震，发生在加尔加诺海角在公元493年，由中世纪神圣的传说报告。1627年7月30日海啸袭击加尔加诺北方海岸后，形成了最小和最新的扇形。
Abstract. The Lesina coastal barrier is characterized by the presence of three wide washover fans. They were formed by three distinct tsunamis which struck the northern coast of the Gargano Promontory (Apulia, Italy) during historical times. A model for their formation is presented. It takes into account the geomorphological data collected and some reports about the effect of recent tsunamis on coastal barriers and beaches. Washover fans were produced by tsunami waves which ran through coseismic cracks developed on dune ridges shaping a narrow, straight and relatively deep trench which constitutes the fan throat. Moreover, each tsunami event most likely caused severe erosion of the coastal barrier, shaping erosive grooves across the dune ridges, causing beach cliffs and causing the nourishment of submarine offshore bars. After the tsunami, a phase of coastal barrier recovery began, forming new dune ridges and closing washover fan throats. Morphological, archeological and radiometric data indicate a pre-Roman age for the oldest event, which was dated at 2430 years BP. The second tsunami struck the Lesina coastal barrier with similar magnitude 1550 years BP; it was caused by the strong earthquake that occurred at Gargano Promontory in the year 493 AD as reported by a medieval sacred legend. The smallest and more recent fan formed following the tsunami that hit the northern coast of Gargano on 30 July 1627.