Ocean acoustic tomography water formation and the gyre circulation. Other applications include the measurement of ocean tides, and the estimation of ocean mesoscale dynamics by combining tomography, satellite altimetry, and in situ data with ocean dynamical models. In addition to the decade-long measurements obtained in the North Pacific, acoustic thermometry has been employed to measure temperature changes of the upper layers of the Arctic Ocean basins, which continues to be an area of active interest. using data from acoustic pulses sent from one end of the earth to the other. Acoustic thermometry is an idea to observe the world's ocean basins, and the
Largest organisms over . The largest organism in the world, according to mass, is the aspen tree whose colonies of clones can grow up to five miles long. The largest such colony is Pando, in the Fishlake National Forest in Utah. Another form of flowering plant that rivals Pando as the largest organism on earth in breadth, if not mass, is the giant marine plant, "Posidonia oceanica", discovered in the Mediterranean near the Balearic Islands, Spain. Its length is about . It may also be the oldest living organism in the world, with an estimated age of 100,000 years. Green algae are