Geography of Samoa

thumb|right|300px|Map of the Samoan archipelago

thumb|300px|Topography of Samoa.

thumb|right|200px|South east coast of [[Savai'i island.]]

The Samoan archipelago is a chain of 16 islands and numerous seamounts covering in the central South Pacific, south of the equator, about halfway between Hawaii and New Zealand, forming part of Polynesia and of the wider region of Oceania. The islands are Savaiʻi, Upolu, Tutuila, ’Uvea, Taʻū, Ofu, Olosega, Apolima, Manono, Nuʻutele, Niulakita, Nuʻulua, Namua, Fanuatapu, Rose Atoll, Nu'ulopa, as well as the submerged Vailuluʻu, Pasco banks, and Alexa Bank.

Tectonics

The Samoan archipelago has many features that are consistent with a plume-driven hotspot model, including the currently active submarine volcano Vailuluʻu that anchors the eastern extremity. However, the chain's proximity to the northern end of the Tonga trench, and the presence of voluminous young volcanism on what should be the oldest (~5 my) western island Savaiʻi has induced controversy regarding a simple plume/hotspot model. The Samoan archipelago was most likely created by the Pacific Tectonic Plate traveling over a fixed hotspot. The Samoa hotspot trail is in part coincident with a large group of islands and seamounts long, which were probably formed by the same hotspot, but also intersect with older seamounts along the hotspot highway left by the Macdonald, Rurutu, and Rarotonga hotspots and feature substantial postshield volcanism, probably owing to tectonic phenomena triggered by the subduction of the Pacific Plate under the Australian Plate at the nearby Tonga Trench.

Vailuluʻu is a volcanic seamount discovered in 1975. It rises from the sea floor to a depth of and is located between Tau and Rose islands at the eastern end of the Samoa hotspot chain. The basaltic seamount is considered to mark the current location of the Samoa hotspot. The summit of Vailuluu contains a wide, deep oval-shaped caldera. Two principal rift zones extend east and west from the summit, parallel to the trend of the Samoan hotspot. A third less prominent rift extends southeast of the summit. Some seamounts in western Samoa ("Samoan Seamounts"), which were emplaced together with Tuvalu between 63 and 42 million years ago are likely remnants of the Rurutu hotspot. These are also known as the "interloper seamounts". Other undated seamounts in Samoa have been linked to the Rurutu hotspot on the basis of geochemical evidence.

Islands of the Samoan archipelago

{| class="wikitable sortable"

! Island

! Area

! Coastline

! Population

! Highest Point

! Last Volcanic Eruption

! Country/Territory

| style="text-align:right; background:#ffffff;"| Savaiʻi

| 1,694

| 195

| 43,142

| 1,858

| 1911 CE

| style="text-align:right; background:#ffffff;"| Upolu

| 1,125

| 197

| 143,418

| 1,113

| Unknown

| style="text-align:right; background:#ffffff;"| Tutuila

| 142.3

| 135

| 55,876

| 653

| 440 CE

| style="text-align:right; background:#ffffff;"| ’Uvea

| 96

| 43

| 8,333

| 131

| Unknown

| style="text-align:right; background:#ffffff;"| Taʻū

| 47.02

| 32

| 790

| 931

| Unknown

| style="text-align:right; background:#ffffff;"| Ofu

| 7.215

| 11.47

| 176

| 491

| 1866 CE

| style="text-align:right; background:#ffffff;"| Olosega

| 5.163

| 13.38

| 172

| 629

| 1866 CE

| style="text-align:right; background:#ffffff;"| Nuʻulua

| 0.23

| 2.78

| 0

| 96

| Unknown

| style="text-align:right; background:#ffffff;"| Nu'ulopa

| 0.01

| 0.45

| 0

| 37

| Unknown

Forests

REDD+ reference level and monitoring

Under the UNFCCC REDD+ framework, Samoa has submitted a national forest reference emission level (FREL) and forest reference level (FRL) package. On the UNFCCC REDD+ Web Platform, the country's 2024 submission is listed as having an assessed reference level, while a national strategy, safeguards information and a national forest monitoring system are all listed as "not reported".

The first assessed FREL/FRL, submitted in 2024 and technically assessed in 2025, covered three REDD+ activities at national scale: reducing emissions from deforestation, reducing emissions from forest degradation, and enhancement of forest carbon stocks. Using a 2013-2022 reference period, the original submission proposed a FREL of 316,245 t CO2 eq per year for deforestation and forest degradation and a FRL of -73,036 t CO2 eq per year for enhancement of forest carbon stocks; these were revised during the technical assessment to an assessed FREL of 278,590 t CO2 eq per year and an assessed FRL of -76,896 t CO2 eq per year. The technical assessment states that the benchmark included above-ground biomass and below-ground biomass, reported CO2 only, and excluded deadwood, litter and soil organic carbon; it also reports that Samoa used a forest definition of at least 1 hectare, 10 percent canopy cover, and trees at least 5 metres tall.

Rose Atoll is the easternmost point of the archipelago and the southernmost point of the United States. American Samoa is home to the National Park of American Samoa.

The highest mountains are: Mt Silisili (Savaiʻi) at , Mount Fito (Upolu) at , Lata Mountain (Taʻū), ; Matafao Peak (Tutuila) at , Piumafua (Olosega) at , and Tumutumu (Ofu) at . Mount Pioa (Tutuila), nicknamed the Rainmaker, is .

American Samoa is also home to some of the world's highest sea cliffs at .

Geography of Samoa

Tectonics

Islands of the Samoan archipelago

Forests

REDD+ reference level and monitoring

References

Sources

See also