How does rising atmospheric CO2 affect marine organisms?

Click to locate material archived on our website by topic

Gulf of Mexico Coastal Hurricane Strikes
Wallace, D.J. and Anderson, J.B. 2010. Evidence of similar probability of intense hurricane strikes for the Gulf of Mexico over the late Holocene. Geology 38: 511-514.

What was done
The authors collected a total of 37 sediment cores along eight transects within Laguna Madre, an elongate water body located behind the narrow low-elevation barrier that is Texas, USA's South Padre Island; and based on the vertical distribution and grain size of storm over-wash sediments contained within four of those cores from two transects -- which were most ideally positioned -- they were able to construct a detailed history of intense hurricane strikes from 5300 to 900 years before present (BP).

What was learned
Based on their analyses, Wallace and Anderson report "there has been no notable variation in intense storm impacts across the northwestern Gulf of Mexico coast during this time interval," i.e., 5300-900 yr BP, "implying no direct link between changing climate conditions and annual hurricane impact probability." In addition, they say "there have been no significant differences in the landfall probabilities of storms between the eastern and western Gulf of Mexico during the late Holocene, suggesting that storm steering mechanisms have not varied during this time."

What it means
In discussing their findings -- as well as the similar results obtained by others for Western Lake, Florida, and Lake Shelby, Alabama -- the two Rice University (Houston, Texas) researchers say that current rates of intense hurricane impacts "do not seem unprecedented when compared to intense strikes over the past 5000 years," and that "similar probabilities in high-intensity hurricane strikes for the eastern and western Gulf of Mexico do not show any clear-cut out-of-phase relationship that would enlighten us as to climate controls on storm pathways." Therefore, they conclude by reiterating that "in the northern Gulf of Mexico, there have been no significant variations in storm impact probabilities and/or storm steering mechanisms from ca. 5300-900 yr BP."

Reviewed 15 September 2010