Iceberg: tabular berg and more

pg 4

"A tabular berg with a mesa top."

In addition to size classification, icebergs can also be classified on the basis of their shape. The two basic types of iceberg forms are tabular and non-tabular. Tabular icebergs have steep sides and a flat top, much like a plateau, with a length-to-height ratio of more than 5:1. This type of iceberg can be quite large, as in the case of Pobeda Ice Island. Antarctic icebergs formed by breaking off from an ice shelf, such as the Ross Ice Shelf or Filchner-Ronne Ice Shelf, are typically tabular. The largest icebergs in the world are formed this way.<{? Non-tabular icebergs have different shapes, and include:
* Dome: An iceberg with a rounded top.
* Pinnacle: An iceberg with one or more spires.
* Wedge: An iceberg with a steep edge on one side and a slope on the opposite side.
* Dry-Dock: An iceberg that has eroded to form a slot or channel.
* Blocky: An iceberg with steep, vertical sides and a flat top. It differs from tabular icebergs in that its shape is more like a block than a flat sheet.
[By definition, a tabular iceberg has a flat top surface, so "mesa top" is redundant. Mesa is a term used for land formations of this kind.]

The huge ice mass looked like a ghostly clipper ship under full sail

A clipper was a very fast sailing ship of the 19th century that had three or more masts and a square rig. They were generally narrow for their length, could carry limited bulk freight, small by later 19th century standards, and had a large total sail area. Clipper ships were mostly made in British and American shipyards, though France, the Netherlands and other nations also produced some. Clippers sailed all over the world, primarily on the trade routes between the United Kingdom and its colonies in the east, in trans-Atlantic trade, and the New York-to-San Francisco route round Cape Horn during the California Gold Rush. Dutch clippers were built beginning in 1850s for the tea trade and passenger service to Java.
The boom years of the Clipper Ship Era began in 1843 as a result of the growing demand for a more rapid delivery of tea from China. It continued under the stimulating influence of the discovery of gold in California and Australia in 1848 and 1851, and ended with the opening of the Suez Canal in 1869

The Boeing, its four engines still turning at reduced power, swept over the stately iceberg like a monstrous Mesozoic bird in search of its primeval nest.

The Mesozoic Era is an interval of geological time from about 250 million years ago to about 65 million years ago. It is often referred to as the Age of Reptiles because reptiles, namely dinosaurs, were the dominant terrestrial and marine vertebrates of the time. The era began in the wake of the Permian-Triassic event, the largest mass extinction in Earth's history, and ended with the Cretaceous–Paleogene extinction event, another mass extinction which is known for having killed off non-avian dinosaurs, as well as other plant and animal species.
Mesozoic means "middle life", deriving from the Greek prefix meso-/μεσο- for "between" and zōon/ζωον meaning "animal" or "living being". It is one of three geologic eras of the Phanerozoic Eon, preceded by the Paleozoic ("ancient life") and succeeded by the Cenozoic ("new life"). The era is subdivided into three major periods: the Triassic, Jurassic, and Cretaceous, which are further subdivided into a number of epochs and stages.
The Mesozoic was a time of significant tectonic, climate and evolutionary activity. The era witnessed the gradual rifting of the supercontinent Pangaea into separate landmasses that would eventually move into their current positions. The climate of the Mesozoic was varied, alternating between warming and cooling periods. Overall, however, the Earth was hotter than it is today. Non-avian dinosaurs appeared in the Mid-Triassic and became the dominant terrestrial vertebrates early in the Jurassic, occupying this position for about 135 million years until their demise at the end of the Cretaceous. Birds first appeared in the Jurassic, having evolved from a branch of theropod dinosaurs. The first mammals also appeared during the Mesozoic, but would remain small and modest until the Cenozoic.