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Mariana Islands

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The Mariana Islands are a crescent-shaped archipelago in the western Pacific Ocean. They consist of fifteen volcanic mountain summits. These islands sit between the 12th and 21st parallels north. They also lie along the 145th meridian east. The islands mark the eastern limit of the Philippine Sea. Geographically, they are part of the Micronesia sub-region.

Philippine Sea location
Philippine Sea location

Politically, the islands are divided into two United States jurisdictions. The southern end consists of the territory of Guam. The northern islands form the Commonwealth of the Northern Mariana Islands. This commonwealth includes islands such as Saipan, Tinian, and Rota. The archipelago is split into two distinct geographic subgroups. The northern group contains ten volcanic main islands. These islands are currently uninhabited. The southern group contains five coralline limestone islands. These include Rota, Guam, Aguijan, Tinian, and Saipan. All are inhabited except for Aguijan.

Map of the Northern Mariana Islands admin
Map of the Northern Mariana Islands admin

The islands formed through complex geologic processes. They are part of the Izu–Bonin–Mariana Arc system. This system is a highly active convergent plate boundary. This means two tectonic plates are moving toward each other. The western edge of the Pacific Plate moves westward. It plunges downward below the Mariana plate. This process is known as subduction. As the plate sinks, it carries water trapped in its faults. This water is known as serpentinite. Deep in the Earth, the temperature rises. This heat turns the water into steam. The pressure from this expanding steam causes hydrothermal and volcanic activity. This activity built the islands over time.

Philippine Sea location
Philippine Sea location

Just east of the islands lies the Mariana Trench. This is the lowest part of the Earth's crust. It is also the deepest part of the world's oceans. The islands are the southern part of a submerged mountain range. This range extends from Guam toward Japan. In the northern volcanic group, some islands have craters. These craters show signs of activity. Earthquakes also occur in this region. The southern islands are lower in elevation. Coral reefs fringe the coasts of these southern isles.

Philippine Sea location
Philippine Sea location

The history of the islands began with the Chamorro people. Archaeologists believe they arrived from the Philippines around 1500 to 1400 BCE. This may have been the longest uninterrupted ocean voyage in human history. These migrants were part of the Austronesian expansion. They brought specific pottery styles to the islands. This pottery featured red-slipped and circle-stamped designs. These designs are similar to pottery found in the Philippines. Genetic studies support this connection. DNA shows the Chamorro people have ancestry from the Philippines.

Chronological dispersal of Austronesian people across the Pacific
Chronological dispersal of Austronesian people across the Pacific

Between 900 and 1700 CE, the islands experienced the Latte period. This era was defined by massive stone structures. These are called latte stones. They consist of two main parts. The first is the haligi, which is a stone pillar. The second is the tasa, a stone cap. The tasa was placed on top of the haligi. This design prevented rodents from climbing the posts. These pillars supported wooden buildings.

Guma Taga ruins, pre-1902
Guma Taga ruins, pre-1902

European contact began in the early 16th century. Ferdinand Magellan led a Spanish expedition to the islands in 1521. The islands were named after Queen Mariana of Austria. Magellan's crew found fresh fruits on the islands. These fruits saved the sailors from scurvy. Scurvy had already killed dozens of his crewmembers. However, the encounter with the Chamorro people was difficult. The Spanish called the islands Islas de los Ladrones. This means "Islands of the Thieves." They used this name after a disagreement over items taken from their ships.

The environment of the Marianas is lush and green. Most islands are densely forested. The vegetation is similar to that of the Philippines. The soil is moist, which supports many plants. This moisture allows cryptogams to grow in large numbers. The climate is warm and damp. However, trade winds temper the heat. This makes the temperature milder than in the Philippines. The islands provide a plentiful supply of water for life.

Chamorro red rice
Chamorro red rice
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🖼️ Images & Media (9)
File:Philippine Sea location.jpg
Philippine Sea location.jpg
File:Chronological dispersal of Austronesian people across the Pacific.svg
Chronological dispersal of Austronesian...
File:Guma Taga ruins, pre-1902.jpg
Guma Taga ruins, pre-1902.jpg
File:Reception of the Manila Galleon by the Chamorro in the Ladrones Islands, ca. 1590.jpg
Reception of the Manila Galleon by the...
File:Estampilla española de las Islas Marianas 5 cent 1898-99.jpg
Estampilla española de las Islas Marianas...
File:Stamp Mariana Islands 1901 20pf.jpg
Stamp Mariana Islands 1901 20pf.jpg
File:A member of a Marine patrol on Saipan found this family of Japs hiding in a hillside cave. The mother, four children an - NARA - 532380.jpg
A member of a Marine patrol on Saipan...
File:Map of the Northern Mariana Islands admin.png
Map of the Northern Mariana Islands admin.png
File:Chamorro red rice.png
Chamorro red rice.png
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