Abstract Decades of space exploration reveal that Mars has been reshaped by volcanism throughout its history. The range of observed volcanic landforms shows that effusive and explosive eruptions have occurred, albeit unevenly in time and space. Evidence for explosive volcanism—characterized as eruptions in which magma is disrupted by the expansion of gases dissolved in magma or by an interaction of magma with external volatiles—is less common than evidence for effusive activity. Nonetheless, some indications of explosive volcanism have been identified at various sites. For instance, old, rimless depressions, termed paterae, on the summits of broad topographic rises with very gentle flanks located mainly around the Hellas impact basin. Also various fields of kilometre-sized cones interpreted as scoria cones, tuff rings and tuff cones, and extensive clusters of sub-kilometre-sized pitted cones in the northern lowlands proposed to be rootless cones, are thought to be constructional features caused by accumulation of volcanic fragments. Finally layered deposits widely spread in equatorial areas (e.g., the Medusae Fossae Formation), and layered stacks of ash and a putative volcanic bomb observed by rover, point to a protracted history of explosive volcanism on Mars. Yet some of these interpretations remain the matter of scientific debate. The discovery of explosive volcanism on Mars has triggered an interest in theoretical aspects of such volcanism under gravitational and atmospheric conditions different from those on Earth. These studies indicate that explosive eruptions on Mars would behave differently from those on Earth. This is because a lower atmospheric pressure and gravity can affect all stages of the eruption including the ascent of magma, the process of degassing and magma fragmentation, the transport and deposition of the pyroclasts, and also in some cases the formation of explosive volcanoes themselves. On Earth, explosive eruptions are responsible for the formation of most volcanoes on land, and so a relatively sparse occurrence of explosive volcanism on Mars is surprising, especially considering the martian environmental conditions as well as wide occurrence of external volatiles on Mars. This is because the lower atmospheric pressure than on Earth ought to favour magma fragmentation and hence the formation of pyroclasts and associated explosive volcanic edifices, even if lower volumes of dissolved gases were present in martian magma than is usual on Earth. The relative dearth of explosive activity on Mars therefore represents a gap in our understanding of martian volcanism, suggesting that there may be considerable compositional differences between Mars and Earth or that evidence of explosive volcanism on Mars manifests differently to on Earth. Understanding these differences is important, as explosive volcanism provides insight about the planet’s composition and plays a crucial role in the evolution of a planet’s atmosphere by the release of magmatic gases, which have the ability to affect geological and even biological processes operating on the surface of the planet. In this paper, we present an overview of explosive volcanism on Mars—from both observational and theoretical perspectives—and discuss the implications of explosive eruptions for the evolution of the Red Planet.

中文翻译：

---

火星上爆发性火山活动的概述

摘要 数十年的太空探索表明，火星在其历史上一直被火山活动重塑。观察到的火山地貌范围表明，虽然时间和空间不均匀，但发生了喷发和爆炸性喷发。爆炸性火山活动的证据——其特征是岩浆被溶解在岩浆中的气体膨胀或岩浆与外部挥发物的相互作用所破坏的喷发——不像喷发活动的证据那么常见。尽管如此，已经在不同地点发现了一些爆炸性火山活动的迹象。例如，古老的、无缘的洼地，被称为 paterae，位于广阔的地形隆起的顶部，侧面非常平缓，主要位于希腊撞击盆地周围。也被解释为火山渣锥体、凝灰岩环和凝灰岩锥体的千米级锥体的各个领域，北部低地大量亚公里大小的有坑锥体群被认为是无根锥体，被认为是火山碎片堆积造成的构造特征。最后，在赤道地区广泛分布的层状沉积物（例如 Medusae Fossae 组），以及火星车观察到的层状火山灰和推定的火山弹，表明火星上爆发性火山活动的历史由来已久。然而，其中一些解释仍然是科学辩论的问题。火星上爆炸性火山活动的发现引发了人们对这种火山活动在不同于地球的引力和大气条件下的理论方面的兴趣。这些研究表明，火星上的爆炸性喷发行为与地球上的不同。这是因为较低的大气压力和重力会影响喷发的所有阶段，包括岩浆的上升、脱气和岩浆破碎的过程、火山碎屑的运输和沉积，在某些情况下还会影响爆炸性火山本身的形成。在地球上，陆地上大部分火山的形成都是由爆炸性喷发造成的，因此火星上相对稀少的爆炸性火山活动令人惊讶，特别是考虑到火星的环境条件以及火星上广泛存在的外部挥发物。这是因为比地球低的大气压力应该有利于岩浆破碎，从而形成火山碎屑和相关的爆炸性火山建筑物，即使火星岩浆中的溶解气体量比地球上通常的要少。因此，火星上爆炸活动的相对缺乏代表了我们对火星火山活动的理解存在差距，这表明火星和地球之间可能存在相当大的成分差异，或者火星上爆炸性火山活动的证据与地球上的表现不同。了解这些差异很重要，因为爆炸性火山活动提供了对行星组成的洞察，并通过释放岩浆气体在行星大气演化中发挥着至关重要的作用，岩浆气体能够影响在地表运行的地质甚至生物过程。星球。在本文中，