In historic times, two catastrophic fissure eruptions originated in the Eastern Volcanic Zone of Iceland, known as Eldgjá eruption (934–940 CE) and Laki eruption (1783–1784 CE). Eldgjá produced 19.7 km3 of lava flows and 1.3 km3 of tephra; Laki emitted 14.7 km3 of lavas and 0.4 km3 of tephra. They released 232 and 122 megatons of SO2 into the atmosphere, respectively. Abundant historic descriptions of the effects of the Laki eruption indicate that the SO2 release produced a sulphuric aerosol that spread across the northern hemisphere with devastating impacts on the population and the environment, especially in Europe. In this study, we present two new written sources that enable the effects of the Eldgjá and Laki eruptions to be fixed to an exact date and place of occurrence in North Africa. These are a medieval North African chronicle known as Rawḍ al-Qirṭās, written in 1326 CE and describing events in Morocco, and a chronicle of events in the island of Djerba (southern Tunisia), written by Muhammad b. Yusef al-Musabi in 1792–1793 CE. These previously unrecognized sources describe in detail the fading of sunlight coupled with the persistent presence of a thick fog made up of fine particles carried over from long distances. The chronicles report events in Morocco in the time period October 938–October 939 CE, and in Tunisia in the year 1783 CE. These data can be interpreted as the first detailed evidence of the consequences of the Eldgjá and Laki eruptions in North Africa. They also can be helpful in dating and determining the area of influence of the eruptions; this may be useful for several applications, such as the numerical simulation of these events, or hazard planning in case of possible future similar eruptions from the same Icelandic area.

中文翻译：

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934–940 CE Eldgjá 和 1783–1784 CE Laki 喷发（冰岛）对北非的影响由以前无法识别的书面资料显示

在历史时期，两次灾难性的裂隙喷发起源于冰岛东部火山带，称为 Eldgjá 喷发（公元 934-940 年）和拉基火山喷发（公元 1783-1784 年）。Eldgjá 产生了 19.7 平方公里的熔岩流和 1.3 平方公里的火山灰；Laki 排放了 14.7 平方公里的熔岩和 0.4 平方公里的火山灰。它们分别向大气中释放了 232 和 122 兆吨二氧化硫。对拉基火山喷发影响的大量历史描述表明，二氧化硫的释放产生了一种硫磺气溶胶，扩散到整个北半球，对人口和环境造成了毁灭性的影响，尤其是在欧洲。在这项研究中，我们提供了两个新的书面资料，可以将 Eldgjá 和 Laki 喷发的影响固定到北非发生的确切日期和地点。这些是被称为 Rawḍ al-Qirṭās 的中世纪北非编年史，写于公元 1326 年，描述了摩洛哥的事件，以及穆罕默德 b. 撰写的杰尔巴岛（突尼斯南部）的事件编年史。尤瑟夫·穆萨比 (Yusef al-Musabi)，公元 1792-1793 年。这些以前未被识别的来源详细描述了阳光的消退以及由远距离携带的细颗粒组成的浓雾的持续存在。编年史记载了公元 938 年 10 月至公元 939 年 10 月期间摩洛哥发生的事件，以及公元 1783 年突尼斯发生的事件。这些数据可以解释为北非 Eldgjá 和 Laki 喷发后果的第一个详细证据。它们还有助于确定火山爆发的影响范围；这可能对多种应用有用，