Sea-surface temperatures at the time of the sinking were in the upper 20s, close to the freezing level of salt water, an indication that the ship literally was in ice water.
Last week, temperatures were in the 50s near the disaster site.
What was different a century ago?
The sinking occurred in a period of worldwide cooling. According to the National Climate Data Center database, which dates to 1880, annual global temperatures for the 15 years preceding the accident were below long-term averages.
One intriguing theory is that the cooling got an extra kick from the 11-year sunspot cycle. NASA data show a tremendous lull in sunspots - violent solar storms that eject powerful energy into space - from late 1910 through mid-1914. Lulls have been associated with global cooling, and the activity hit rock bottom in 1913, which saw 314 days without a single sunspot.
In a paper published in 2000, British meteorologist Edward N. Lawrence hypothesized that cooling would have reached a peak as sunspot activity approached its lowest level.
Spring is an especially dangerous period for icebergs in any year because warmth loosens ice. With temperatures subtly rising and glaciers melting, icebergs remain common North Atlantic hazards, said Alex Sosnowski, meteorologist with Accu-Weather Inc. Typically, however, they are "growlers" or "bergy bits" and range from 3.3 to 16 feet high.
However, the iceberg situation of April 1912 evidently was extreme. General cooling would have contributed to a prodigious ice supply, and it's possible that a warm interval along the Greenland coast caused some of that ice to break loose.
The one that struck the Titanic was as high as 200 feet and as wide as 400 feet, and it had traveled unusually far south, to a latitude of about 41.5 degrees.
The Institute for Ocean Technology, in Canada, has documented more than 550 ship-iceberg collisions in the North Atlantic, dating to the mid-19th century, but only a few have occurred at that latitude.
What's more, the Titanic ended up among a mass of icebergs.
Rodney Viereck, a solar specialist at the government's Space Weather Prediction Center, in Colorado, believes Lawrence was on to something with the solar connection.
While no one would blame sunspots for the disaster, they may well have played a role, he said last week.
"There is significant evidence to show that the cold climate of 1912 may have been in part due to the lower level of solar energy reaching Earth relative to today," he said.
Precisely how subtle changes in solar energy affect Earth's climate is uncertain; the range in output is a mere 0.2 percent, experts say. Nor has anyone quite figured out how to separate it from other forces, such as human activity, volcanic ash, or changing ocean temperatures.
Yet, long-observed solar fluctuations almost certainly have significant impacts on climate. Viereck said sunspot observations represented some of the oldest reliable data in the climate record; Galileo made observations of sunspots as early as 1612. It is known that in the heart of the Little Ice Age, none was sighted from 1661 to 1671.
While they may have had something to do with the Titanic disaster, human error, no doubt, was a bigger factor.
Contact Anthony R. Wood
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