Here’s another chance to play geographical detective! These natural-color images were acquired by the Multi-angle Imaging SpectroRadiometer (MISR) during October and November 2003. The two images represent about 310 kilometers x 141 kilometers (right panel) and 310 x 184 kilometers (left panel). This mystery concerns two coral atoll ecosystems located in different parts of the globe.
Use any reference materials you like to answer the following 4 questions.
1. Three of these four statements about the geomorphology of the coral reefs are true. Which one is false?
nbsp; (A) Their modern shape has been influenced by sea level changes over geologic
timescales.
nbsp; (B) The reefs have grown over millions of years atop ancient volcanic mountain
ranges.
nbsp; (C) Unless there is too much sediment present in the water, some of the
reefs can grow at depths of up to 170 meters.
nbsp; (D) The reefs tend to grow in density and thickness where the water flow
is greatest due to prevailing ocean currents.
2. Three of the following four statements accurately describes coral atoll ecosystems. Which one does not?
nbsp; (A) Other living organisms besides coral help to build the atolls
through calcium carbonate production.
nbsp; (B) Symbiotic zooxanthellae provide reef corals with the calcium and
nutrients they need to grow.
nbsp; (C) Atolls can be very open, entirely closed, or have a number of entry
points by which a lagoon area is open to the ocean.
nbsp; (D) The diversity and abundance of corals is greater along the protected
inner atoll and lagoon areas than along the outer reef slopes.
3. Three of these four statements about the atolls of the left-hand
image are true. Which one is false?
nbsp; (A) The many small saucer-shaped reef structures within the lagoonal
areas make this reef system different from all others.
nbsp; (B) The word "atoll" is a term that comes from a language native to this
region, and has been expanded for use worldwide.
nbsp; (C) The two largest cities in these atolls are home to about 8000 people
each.
nbsp; (D) At one atoll, construction of an artificial reef began in November 2001.
4. Three of these four statements about the atolls of the right-hand
image are true. Which one is false?
nbsp; (A) In this region the prevailing ocean current, or swell, comes from
the south.
nbsp; (B) The chemical character of the inner lagoons is not significantly
influenced by the size of the openings in the reef rims.
nbsp; (C) Within the image area there is a designated biosphere reserve and
breeding grounds for at least 3 species of sea turtle.
nbsp; (D) The most extensive freshwater is found at the small, round, green
atoll that appears along the left-hand image edge.
E-mail your answers, name (initials are acceptable if you prefer), and your hometown by the quiz deadline of Tuesday, December 2, 2003, to suggestions@mail-misr.jpl.nasa.gov .
Answers will be published on the MISR web site . The names and home towns of respondents who answer all questions correctly by the deadline will also be published in the order responses were received. The first 3 people on this list who are not affiliated with NASA, JPL, or MISR and who have not previously won a prize will be sent a print of the image.
A new "Where on Earth...?" mystery appears as the MISR "latest featured image" approximately once every two months. New featured images are released on Wednesdays at noon Pacific time on the MISR home page.
Image courtesy NASA/GSFC/LaRC/JPL, MISR Team. Text by Clare Averill, Raytheon
