2023年1月23日

Professor of Earth and Environmental Sciences Uses the Tools of His Trade at Moroccan Ruins

作为地球物理学家, Ahmed Lachhab never imagined he would be applying the same tools he uses to study lakes in Pennsylvania to help archeologists in Morocco.

然而，在一个 article 发表在学术期刊《浩博体育app网站》上, Lachhab, associate professor of earth and environmental sciences at 浩博体育app, lays out how he used ground-penetrating radar to help archeologists preserve ancient Roman mosaics at Volubilis, 摩洛哥西北部的联合国教科文组织世界遗产.

“Volubilis is an ancient Roman city that dates to about the third century B.C.拉合解释说. “It was a prosperous city marked by attractive villas with large mosaic floors that illustrate ancient Roman mythology.”

Lachhab first encountered Volubilis in 2018 when he began taking students there through 浩博体育app’s Global Opportunities study-abroad program. 在GO摩洛哥的经历中, 学生s engaged in a daylong workshop where they explore Volubilis, its history and learn how to restore sections of the damaged Roman mosaics.

罗马人按照规定的方式建造马赛克, 在土壤和巨石的基础上分层砂浆. 在随后的几年里, 马赛克的基础已经发生了变化, 导致马赛克变得不平整, 断裂并与周围的墙壁分离.

1940年至1950年间，该遗址首次进行了修复, archaeologists lifted the mosaic and re-laid it over rebar-enforced concrete slabs,拉合说. “This is a very labor-intensive process that is nearing the end of its lifespan, 也就是说这些马赛克又需要修复了.”

而不是, Lachhab proposed using the tools of his trade – laser level survey, drone photogrammetry and ground-penetrating radar — at Volubilis’ House of Venus and the House of Dionysos. 作为地球物理学家, Lachhab normally uses these techniques to determine the volume of water and sediment deposits in lakes and man-made reservoirs. 在瓦卢, 他研究了三幅镶嵌画:狄俄尼索斯和四季, 戴安娜的沐浴，巴克斯和四季.

He first used a self-leveling laser to survey the surface of the mosaic, 注意到涟漪和下沉在哪里. He then used a drone to take a series of detailed photographs of these mosaics and created 3D photogrammetry models and orthomosaics maps (a series of photos pieced together to create a larger detailed images) to inspect surface features and accurately measure their spatial dimensions. 最后, Lachhab surveyed the mosaics using ground-penetrating radar to collect 2D profiles and create 3D diagrams of the mosaic layer down to 50 cm depth. ​

“The integration of the three techniques was proven to be necessary to assess the actual state of these mosaics,拉合说. “最重要的是, the GPR shows the presence of void spaces — places where the land has settled — sometimes on both sides of the concrete slab, as well as the presence of fissures that are both restricted internally beneath the mosaic and/or crossing the entire mosaic layer all the way to the surface.”​

其他考古学家对拉合的研究方法感兴趣 

戴安娜浴池，瓦勒比利斯的古罗马镶嵌画现在, 而不是抬起整个马赛克, the archaeologists used Lachhab’s maps to locate any areas of void beneath the mosaic and fill only that space with binding material, 使用注射器插入马赛克.

“It’s a much more noninvasive method when beginning the restoration process on these ancient works of art拉合解释说.

Lachhab presented his findings at a recent meeting of the 国际 Committee for the Conservation of Mosaics in Bulgaria. 可能是房间里唯一的地球物理学家, he was approached by other archaeologists eager to have him survey their sites elsewhere in Bulgaria and Greece.

“这是考古学领域的一个突破，”拉哈布说. “It gives a good feeling to be preserving these precious mosaics that have been there for over 2,000年. 我也很享受这个学习的过程, 这是Susquehanna的GO项目带来的.”