WEST INDIES

<body topmargin=0 leftmargin=0 marginheight=0 marginwidth=0> <table cellpadding=0 cellspacing=0 border=0><tr> <td valign="top" colspan=2 height=90 BGCOLOR="#006699" TEXT="#080000" background="0a9fd5a3.jpg"> <div> <B> </B><FONT SIZE="6" COLOR="#FF0000" FACE="Arial" ><B><IMG SRC="0b1c52d0.gif" border=0 width="197" height="45" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></FONT><B>   </B><B> |     </B><A HREF="index.htm" TARGET="_top" TITLE="_"><U><B>home</B></U></A><B>                                                    </B><FONT SIZE="7" COLOR="#FF0000" FACE="Arial" ><B>AstroGeoData</B></FONT></div> <div> <B>WEST INDIES</B></div> <div> </div> </td> </tr><tr> <td valign="top" width=210 BGCOLOR="#FFCC66" TEXT="#080000" background="0aad2043.jpg"> <div>          <FONT SIZE="2" COLOR="#FF0000" FACE="Arial" ><A HREF="id29.htm" TARGET="_top" TITLE="DATA"><U><B>Back to DATA</B></U></A></FONT></div> <bR> <div> <B>        </B><A HREF="id65.htm" TARGET="_top" TITLE="ATLANTIC"><U><B>Back to ATLANTIC</B></U></A></div> </td> <td valign="top" height=390 BGCOLOR="#FF6633" TEXT="#080000"> <div> <I><B>WEST INDIES</B></I></div> <div> <IMG SRC="2dc46c20.gif" border=0 width="582" height="450" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></div> <div> <B>GEOLOGICAL SETTING</B></div> <bR> <div> <A HREF="http://thepedia.com/define/Caribbean_Plate" TARGET="_top" TITLE="http://thepedia.com/define/Caribbean_Pla"><U><U>http://thepedia.com/define/Caribbean_Plate</U></U></A></div> <bR> <bR> <div> <IMG SRC="2df5d060.png" border=0 width="349" height="262" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></div> <bR> <bR> <div> "The <B>Caribbean Plate</B> is an oceanic <FONT SIZE="3" COLOR="#0000FF" FACE="Arial" ><U>tectonic plate</U></FONT> that encompasses roughly 3.2x10<FONT SIZE="1" COLOR="#000000" FACE="Arial" >6</FONT> km² and underlies <FONT SIZE="3" COLOR="#0000FF" FACE="Arial" ><U>Central America</U></FONT> and the <FONT SIZE="3" COLOR="#0000FF" FACE="Arial" ><U>Caribbean Sea</U></FONT> off the north coast of <FONT SIZE="3" COLOR="#0000FF" FACE="Arial" ><U>South America</U></FONT>. The Caribbean Plate borders the <FONT SIZE="3" COLOR="#0000FF" FACE="Arial" ><U>North American Plate</U></FONT>, the <FONT SIZE="3" COLOR="#0000FF" FACE="Arial" ><U>South American Plate</U></FONT>, and the <FONT SIZE="3" COLOR="#0000FF" FACE="Arial" ><U>Cocos Plate</U></FONT>. These borders are hotspots for <FONT SIZE="3" COLOR="#0000FF" FACE="Arial" ><U>seismic</U></FONT> activity, including frequent <FONT SIZE="3" COLOR="#0000FF" FACE="Arial" ><U>earthquakes</U></FONT> and tremors, occasional <FONT SIZE="3" COLOR="#0000FF" FACE="Arial" ><U>tsunamis</U></FONT>, and <FONT SIZE="3" COLOR="#0000FF" FACE="Arial" ><U>volcanic</U></FONT> eruptions".</div> <bR> <div> _________________________________</div> <bR> <bR> <div> <B>CARIBBEAN</B></div> <bR> <bR> <div> <B><IMG SRC="584aa750.png" border=0 width="426" height="373" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></div> <div> Seventeen volcanoes have been active in the West Indies in the Holocene (the last 10,000 years). Most of these volcanoes are subearial and form parts of islands.</div> <bR> <bR> <bR> <div> <B><IMG SRC="585d5a90.jpg" border=0 width="469" height="425" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></div> <bR> <bR> <bR> <div> <B><IMG SRC="5867cfe0.jpg" border=0 width="380" height="254" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></div> <div> The volcanoes of the West Indies result from the <FONT SIZE="3" COLOR="#0000FF" FACE="Arial" ><U>subduction</U></FONT> of oceanic lithosphere, created at the <B>Mid-Atlantic Ridge</B>, beneath the east edge of the Caribbean Plate. The volcanoes of Central America are the result of subduction of the Cocos Plate beneath the west edge of the Caribbean Plate. Arrows show the direction of plate motion. Black "teeth" are on the overriding plate at subduction zones. Map simplified from Montgomery and others (1994). </div> <bR> <bR> <div> <B><IMG SRC="588f41e0.jpg" border=0 width="500" height="542" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></div> <div> Correlation between the Caribbean Plate and the Mid-Atlantic Ridge.</div> <bR> <bR> <bR> <div> <B><IMG SRC="58af2780.png" border=0 width="498" height="376" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></div> <bR> <div> <B><IMG SRC="58bfab60.png" border=0 width="250" height="182" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></B></div> <div> The Mid-Atlantic Ridge is a 10,000 mile long north-south mountain chain occupying the center of the Atlantic Ocean and passing through Iceland. It is the most extensively studied divergent plate boundary, dividing the North and South America Plates from the Eurasian and African Plates. In the divergent plate boundary, molten magma continuously rises from the mantle to the sea floor to fill in the gap formed by the diverging plates, and thus creating seafloor spreading. It is estimated that the Atlantic Ocean sea floor expands at a rate of 0.5 to 4 inches annually.</div> <bR> <div> In addition to its divergent plate boundaries, the curving of the ridge also creates a number of transform fault lines. Occasionally, these transform faults are the site of seismic activity as the adjacent plates move in northern or southern directions.</div> <bR> <div> <B>________________________________________________</B></div> <div> <B>________________________________________________</B></div> <bR> <bR> <div> <B>VOLCANOES:</B></div> <bR> <div> <A HREF="id226.htm" TARGET="_top" TITLE="SOUFRIERE HILLS"><U><B>SOUFRIERE HILLS</B></U></A></div> <bR> <bR> <bR> <bR> <div> <IMG SRC="10a46550.gif" border=0 width="70" height="85" ALIGN="BOTTOM" HSPACE="0" VSPACE="0"></div> </td> </tr></table></body>