PHOTOGRAMMETRIC ENGINEERING & REMOTE SENSING
August 2019
537
by
Clifford J. Mugnier, CP, CMS, FASPRS
T
uvalu comprises a chain, 580 kilometers long,
of nine coral atolls in the Pacific Ocean just
west of the International Date Line. The total
land area of the densely populated group is only
26 sq km (10 sq mi); however, the islands occupy
1.3 million sq km (500,000 sq mi) of ocean between
Kiribati and the Samoas. Five of the islands are low-
lying coral atolls; the highest point on these (and the
highest point in Tuvalu) is just 4.6m (15 ft) above
sea level. The remaining four islands are pinnacles
of land that rise up from the sea bed. On the islands,
there are many reefs and salt-water ponds while the
island of Nanumea hosts a fresh-water pond; rare
for an atoll. Made mostly of eroded coral, Tuvalu has
poor soil, no streams or rivers, and few remaining
outcrops of forest. Coconut palms grow in abundance
across all the islands, but otherwise there is only
enough soil to support subsistence agriculture for
about three-quarters of the population. All other
food is imported. Water needs are met by catchment
and storage facilities because the porous, low-lying
atolls are unable to hold ground water. The only
land animals are the Polynesian rat, chickens, dogs,
and pigs — all introduced species. Niulakita has
no lagoon, but has a swamp at its center. Because
it has never had a permanent population, the
southernmost island was not taken into account
in the naming of the Tuvalu group. Tuvalu means
“eight standing together.” The climate is tropical,
with an average temperature of 30ºC (87ºF) and
little seasonal variation. The wet season is between
October andMarch, and 350 cm (12 ft) of rain falls in
a normal year. Cyclone (hurricane) activity is rare;
there have been only four severe hits this century
(but all since 1972).
The Grids & Datums column has completed an exploration of
every country on the Earth. For those who did not get to enjoy this
world tour the first time,
PE&RS
is reprinting prior articles from the
column. This month’s article on Tuvalu was originally printed in
2001 but contains updates to their coordinate system since then.
Physiographically, Tuvalu belongs in Micronesia, but cul-
turally, the islands belong to Polynesia. Language, tradi-
tions, and artifacts indicate that Polynesians from Tonga and
Samoa in the southeast arrived in the island group early in
the 14th century. In 1597, Don Alvaro de Mendaña y Neyra
cruised through the coral atolls of Tuvalu. Further Europe-
an contact came in the late 18th century, and the last of the
islands were charted by 1826. They were named the Ellice
Islands after the British member of parliament who owned
the ship that first landed on Funafuti Atoll in 1819. In 1892,
the islands became part of the Gilbert and Ellice Islands pro-
tectorate and, in 1916, became a Crown Colony. During WWII
the U.S. used Tuvalu’s northernmost atoll, Nanumea, as a
base to repel the Japanese who were threatening the Gilbert
Islands. Wrecks of air and sea craft remain on the island.
From the 1960s through 1977, Tuvaluans embarked on
Photogrammetric Engineering & Remote Sensing
Vol. 85, No. 8, August 2019, pp. 537–539.
0099-1112/19/537–539
© 2019 American Society for Photogrammetry
and Remote Sensing
doi: 10.14358/PERS.85.8.537
