<html> <head> <title>Chroniques volcaniques de Vicki Volka: le volcan Erta Ale</title> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> <meta name="description" content="Les chroniques volcaniques de Vicki Volka ont pour but de vulgariser l'univers des volcans par le biais d'un personnage sympatique portant le nom de... Vicki Volka, une jeune aventurire qubcoise passionne de volcans et de gographie"> <meta name="keywords" content="volcan, volcano, exprience scientifique, vinaigre, farine, vicki, volka, chroniques, science, volcanologie, vulgarisation"> <link rel="stylesheet" href="/style.css" type="text/css"> </head>  <body bgcolor="#FDFF9F" text="#000000" onLoad="MM_preloadImages('/img/volcanD.gif','/img/vickiHistoD.gif','/img/loupeD.gif','/img/terreD.gif','/img/livreD.gif','/img/enveloppeD.gif','/img/chaineD.gif','/img/crayonD.gif','../img/questionMoisD.gif')"> <table width="660" border="0" cellspacing="0" cellpadding="0" align="center">   <tr>      <td colspan="3">        <p align="center" class="RER"><a name="top">L'Erta Ale................................pays          &Eacute;thiopie<br>         coordonn&eacute;es..........13.6 Nord...........40.7 Est<br>         &eacute;l&eacute;vation.................613 m&egrave;tres................</a><br>       </p>       <p align="center" class="par">&nbsp;</p>     </td>   </tr>   <tr>      <td width="141" valign="top">        <p class="par">&nbsp; 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est continue          depuis de nombreuses ann&eacute;es et il se situe dans un <a href="/lexique/lexique.shtml#rift">rift</a>          continental. Il s'agit l&agrave; d'une chose tr&egrave;s s&eacute;rieuse,          la naissance d'un nouvel oc&eacute;an! La <a href="/lexique/lexique.shtml#chaineVolcanique">cha&icirc;ne          volcanique</a> du m&ecirc;me nom que le volcan (</span><span class="RER">Erta          Ale</span><span class="par">) s'&eacute;tend sur 80 kilom&egrave;tres.          Le volcan </span><span class="RER">Erta Ale</span><span class="par"> est          un volcan sym&eacute;trique d'Est en Ouest (image 1) avec une pente voisine          de 2.3&deg; (par rapport &agrave; l'horizontal). Les pentes se joignent          au dessus de 600 m&egrave;tres d'altitude par une <a href="/lexique/lexique.shtml#caldeira">caldeira</a>          de 1600x700 m (image 2). </span>        <p class="par"><span class="par">Le d&eacute;sert de Danakil o&ugrave; l'on          retrouve le volcan Erta Ale est une r&eacute;gion de la Terre o&ugrave;          le climat est tr&egrave;s chaud et sec. C'est l'une des raisons ayant          emp&ecirc;ch&eacute; les scientifiques d'explorer le sommet du volcan          Erta Ale avant la fin des ann&eacute;es 1960. &Agrave; l'aide d'<a href="/lexique/lexique.shtml#imageSatellitaire">images          satellitaires</a>, des <a href="/chronique/oct02/source1.html" target="_blank">scientifiques          d'universit&eacute;s britanniques, C. Oppenheimer et P. Francis</a> ont          publi&eacute; une &eacute;tude en 1998 sur l'activit&eacute; de ce volcan.          Ces scientifiques ont remarqu&eacute; une continuit&eacute; de l'activit&eacute;          du lac de <a href="/lexique/lexique.shtml#lave">lave</a> du volcan Erta          Ale probablement depuis 1906. Le volcan aurait m&ecirc;me poss&eacute;d&eacute;,          certaines ann&eacute;es, deux lacs de lave &agrave; son sommet! Ils ont          &eacute;galement remarqu&eacute; que les calderas du </span><span class="RER">Erta          Ale</span><span class="par"> ont une taille kilom&eacute;trique, voir          plus; c'est grand pour un volcan form&eacute; de laves fluides. Ces scientifiques          ont enfin not&eacute; que peu de coul&eacute;es de lave s'&eacute;taient          &eacute;coul&eacute;es en surface pendant la m&ecirc;me p&eacute;riode.</span>      </td>     <td width="150" height="238" valign="top">        <div align="center">         <p>&nbsp;</p>         <p class="pas">Sch&eacute;ma du volcan Erta Ale</p>         <p class="par"><a href="/chronique/oct02/image3b1.shtml"><img src="/chronique/oct02/img/image3b1_thumb.gif" width="150" height="134" alt="Sch&eacute;ma du Erta Ale" border="0"></a></p>         <p class="par">Clique sur l'image 1 pour plus de d&eacute;tails</p>         <p>&nbsp;</p>         <p>&nbsp;</p>         <p>&nbsp;</p>         <p><span class="pas">Caldeira du volcan Erta Ale</span></p>       </div>       <p align="center" class="pas"><a href="/chronique/oct02/image3b2.shtml"><img src="/chronique/oct02/img/image3b2_thumb.jpg" width="150" height="100" alt="Caldeira du Erta Ale" border="0"></a></p>       <p class="par" align="center">Clique sur l'image 2 pour plus de d&eacute;tails</p>       <p class="par" align="center">&nbsp;</p>       </td>   </tr>   <tr>      <td colspan="3" valign="top">        <table width="509" border="0" cellspacing="0" cellpadding="0">         <tr>            <td width="95" valign="top" height="23">              <div align="center"></div>           </td>           <td width="48"></td>           <td width="41" valign="top">              <table width="100%" border="0" cellpadding="0" cellspacing="0">               <tr>                  <td width="41" height="23" valign="top">                    <div align="center"><img src="/img/vickiSmall.gif" width="25" height="26"></div>                 </td>               </tr>             </table>           </td>           <td width="152" valign="top">                             <p class="PEO" align="right">page &nbsp;&nbsp;1&nbsp;&nbsp;&nbsp;<a href="/chronique/oct02/oct02Page3b2.shtml"><font color="FF6000">2</font></a>&nbsp;&nbsp;&nbsp;<a href="/chronique/oct02/oct02Page3b3.shtml"><font color="FF6000">3</font></a>&nbsp;&nbsp;&nbsp;</p>           </td>           <td width="38" valign="top">              <div align="center"><a href="/chronique/oct02/oct02Page3b2.shtml"><img src="/img/orgrightSmall.gif" width="24" height="24" border="0" alt="page suivante"></a></div>           </td>           <td width="94" valign="top" class="PEO">              <p><a href="/chronique/oct02/oct02Page3b2.shtml"><font color="FF6000">suivante</font></a></p>           </td>           <td width="41" valign="top" class="par">              <p class="par" align="center"><img src="/img/vickiSmall.gif" width="25" height="26"></p>           </td>         </tr>       </table>       <p>&nbsp;</p>     </td>   </tr>   <tr>      <td colspan="3" valign="top">        <div align="center">           <table width="486" border="0" cellspacing="0" cellpadding="0">   <tr>      <td width="124" class="pas">Retour en haut de la page</td>     <td width="49" class="pas">        <div align="left"><a href="#top"><img src="/img/orgup.gif" width="32" height="32" border="0" alt="Haut de la page"></a></div>     </td>     <td width="86" class="pas">Page pr&eacute;c&eacute;dente</td>     <td width="70" class="pas"><a href="javascript:history.back()"><img src="/img/orgleft.gif" width="32" height="32" border="0"></a></td>     <td width="108" class="pas">Retour aux chroniques du mois</td>     <td width="49">        <div align="left"><a href="/chronique/avr03/avr03Page2.shtml"><img src="/img/terre.gif" width="45" height="40" border="0" alt="Page d'accueil"></a></div>     </td>   </tr> </table>          <p>&nbsp;</p>           <p align="center" class="pas"><a href="/index.html">Accueil</a> - <a href="/histo/histoire.shtml">Histoire    de Vicki Volka</a> - <a href="/recherche/recherche.shtml">Recherche</a><br>   <a href="/chronique/avr03/avr03Page2.shtml">Chroniques du mois</a> - <a href="/lexique/lexique.shtml">Lexique</a>    - <a href="/dessin/contactDessin.shtml">Envoyer un dessin</a><br>   <a href="/liens/liensMois.shtml">Liens du mois</a> - <a href="/dessin/dessin.shtml">Dessin    du mois </a>- <a href="/question/questionMois.shtml">Question du mois</a></p>        </div>     </td>   </tr> </table>  </body> </html> 
