Deep-Sea Habitats of the Marshall Islands

Some evidence from the Ratak Chain suggests that its volcanoes are Cretaceous in age and are related to the Rurutu-Arago Hotspot, which is currently located near Arago (also known as Tinomana) Seamount in the Southern Pacific Cook-Austral Islands. The Ralik Chain also formed during the Cretaceous, but it has remained sparsely sampled to date, and its origins are not yet firmly identified.

During NA174, co-lead scientist Dr. Val Finlayson from the University of Maryland will oversee geology efforts, including surveying two parallel volcanic chains within the greater Marshall Islands region, often referred to as “Ralik” and “Ratak”. A small number of volcanoes from these areas have been geochemically characterized, but overall, little remains known about the origins of these volcanoes.

"Lava samples that we aim to recover during NA174 preserve chemical signatures of where and when these volcanoes formed. We can use that information to gain new insights into the geologic history of the Marshall Islands and fill one of the many gaps in our knowledge about Cretaceous volcanic activity in the Western Pacific," she says.

Located midway between Hawaiʻi and the Philippines, the Republic of the Marshall Islands is an island nation in the Central Pacific region of Micronesia. As one of only four atoll-nations in the world, the Republic of the Marshall Islands consists of 29 low-lying atolls and five main islands that are surrounded by over 2.13 million square kilometers of mostly unexplored seafloor. The islands are oriented into two parallel island chains: Ratak in the east and Ralik to the west, which means sunrise and sunset in the Marshallese language, respectively. Each of the 29 atolls consists of a number of islets separating a central lagoon from the surrounding barrier reef, together totaling more than 1,200 individual islets. With a total land area of only 181 square kilometers, 98.9% of the Marshall Islands' territory is underwater - the largest proportion of water to land of any sovereign state.