[Coral-List] Coral Surface Area-Responses

[Tyler Smith]

Fantabulous.   Apparently people have lots of experience estimating  
coral surface area

I'll summarize the advice below:

-(Thanks Ian Enochs and Johnathan Kool) If you just want your cap  
defined from the middle of the ellipsoid, just use twice your height  
to calculate your ellipsoidal SA and then divide the SA in two.  It's  
a very different story if you don't want to have your cap created  
from the center of the ellipsoid and I would look at it here:

http://mathforum.org/library/drmath/view/51805.html

and

http://mathforum.org/library/drmath/view/52133.html (warning:  
mentions calculus and integrals)


-(Thanks Judy Lang and Chris Jeffries) According to Fisher (2007, p.  
53), the surface area of a massive hemisphere can approximated as 2  
times pi times the square of r (radius), where r is estimated as the  
average of all three dimensions, (i.e., LWH)/3).
Fisher, WS 2006. Stony Coral Rapid Bioassessment Protocol. EPA /600/ 
R-06/167

-(Thanks Joe Schittone)
Here's a formula I've used; not 100% accurate, but close. See: http:// 
sanctuaries.noaa.gov/science/conservation/elpis.html.
Used there for boulders, but will work (at least for head/mounding  
corals).
2¹*(a+b)/4*h + ¹*a/2*b/2; where a, b, & h, are the lengths of the  
major and minor axes and height, respectively

-(Thanks Remy Okazakai)
I use domes instead of ellipsoids for my surface area calculations,  
so I don't know if I'll properly address your question.
However, this site has a dome calculator and equations (based on  
architecture).   Maybe you could calculate SA or V for a dome and  
double it for your ellipsoid.

Calculator: http://static.monolithic.com/plan-design/calcs/index.html
Formulas: http://static.monolithic.com/construction/formulas.pdf

-(Thanks Mike Risk)
Rose and Risk, 1985. I don't have a pdf-Marine Biology. We used CAD/CAM
software, worked well, had the same data you have.

-(Thanks Albert Norstršm)
http://en.wikipedia.org/wiki/Spheroid

Cheers,
Tyler



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Tyler B. Smith, Ph.D.
Assistant Professor
Center for Marine and Environmental Studies
University of the Virgin Islands
2 John Brewers Bay
St. Thomas, USVI       00802
USA
office: 340-693-1394
fax:     340-693-1385