The Norman Transcript

Opinion

July 18, 2013

Stalagmites tell climate story

NORMAN — Some of the interesting features of certain caves are stalactites and stalagmites, the column-like features that hang down from the ceiling and are built up from the floor. Humans have known of their existence since time immemorial, but it’s only in recent years we’ve realized they have a story about climate to tell us.

As reported recently in Science Express, researchers led by a team at the Georgia Institute of Technology studied four stalagmites from Borneo. The stalagmites are made of calcite, a relatively soft mineral made of calcium, carbon and oxygen. It’s estimated that the stalagmites in Borneo grow at a rate of about three-eighths of an inch every thousand years.

Stalactites and stalagmites are found in caves because the rainwater of a region penetrates the ground, dissolving a little bit of mineral matter as it moves. When it gets to a cave, the water drips down from the ceiling and onto the floor. Just a little at a time, minerals like calcite are precipitated as the water evaporates a smidgen. The stalactites and stalagmites in Borneo grew over the course of 100,000 years.

What’s especially interesting about the Borneo stalagmites is that the calcite in them has variations in the mineral’s oxygen atoms. Different oxygen atoms on Earth have different atomic weights. The differences in the oxygen weights in the stalagmites reflect different oxygen atoms in the groundwater of an area. That, in turn, is a function of variations in oxygen weights of rainwater that fell in Borneo over millennia.

The researchers investigating the stalagmites cut them lengthwise in half. They took small samples at the center of the stalagmites less than an eighth of an inch apart. The samples show two things: the rainwater of Borneo was influenced by the rapid climate change patterns known from the North Atlantic and called Heinrich events. But the Borneo samples don’t show evidence of being influenced by a different set of northern rapid climate change events, those called the Dansgaard-Oeschger oscillations.

Text Only | Photo Reprints
Opinion
  • Hate without end

    The news that a former grand dragon of the Ku Klux Klan is suspected of shooting and killing three people near Jewish community centers in Kansas seems at first glance like a disparaged past flaring briefly into the present. Americans like ...

    April 21, 2014

  • Reform is necessary

    Editor, The Transcript: Last year, the legislature passed laws reforming the Oklahoma Department of Veterans Affairs, which was a good start, but more is needed. Recent media reports have revealed that the ODVA employs M.D. and D.O. ...

    April 20, 2014

  • Keep your brain cells

    Editor, The Transcript: Hey kids. Four centuries ago, Shakespeare wrote about life’s seven great adventures. I forget his exact words, but they were something like this: 1. Our birth; none of us can remember it, but never the less, it is ...

    April 20, 2014

  • Don’t let moderation confuse you

    Jeb Bush’s recent compassionate comments on immigration show how far apart he is from the far right of the Republican Party....

    April 20, 2014

  • Priest’s execution should spur action

    In the hierarchy of saints, martyrs are on the highest rung of the celestial ladder, at least for me....

    April 20, 2014

  • Settlers found opportunities in red dirt fields

    There are few constants in families where the teenagers and soon-to-be teenagers outnumber their parents. One things holds true at my home: Nobody gets out of bed in the morning before dear old Dad....

    April 20, 2014

  • Necessary services may be reduced

    Editor, The Transcript: There were criticisms of the Oklahoma Senate bill for a test project to privatize management of Medicaid; however, no one mentioned a critical issue of reduced services for the more needy of our society....

    April 20, 2014

  • Enforcement not the issue

    Editor, The Transcript: The government is legally right in the U.S. Government vs. Bundy Ranch matter....

    April 20, 2014

  • Family thanks community, takes issue with photo

    Editor, The Transcript: As I write this, it’s been almost eight weeks since Feb. 17, the day my family’s home burned in a fire. We lost our 15-year-old cat, Misti; 7-year-old dog, Sully; 3-year-old rescue squirrel, Rocky; almost 2-year-old ...

    April 20, 2014

  • Dancing forward

    The official motto for Mike Fowler’s chairmanship of the Norman Chamber of Commerce is “Moving Norman Forward.” But after Thursday night’s annual banquet, the sub-theme should be, “Let’s Dance, Norman.” More than 500 chamber members and ...

    April 19, 2014