Blabk page and can't get into admin

when I go to http://aresnyc.org/ I'm presented with a blank page in firefox and a 500 error in IE10 and crome a Error code: 500 server error
all my other sites are up. checked dns at enom all is normal
checked error log in root
see this error
[01-Aug-2013 16:26:47 UTC] PHP Warning: Invalid argument supplied for foreach() in /home/xxxxxx/public_html/wp-includes/query.php on line 1702
[01-Aug-2013 16:26:47 UTC] PHP Fatal error: Call to a member function is_main_query() on a non-object in /home/xxxxxx/public_html/wp-includes/query.php on line 724
[01-Aug-2013 16:26:52 UTC] PHP Warning: Invalid argument supplied for foreach() in /home/xxxxxx/public_html/wp-includes/query.php on line 1702
[01-Aug-2013 16:26:52 UTC] PHP Fatal error: Call to a member function is_main_query() on a non-object in /home/xxxxxx/public_html/wp-includes/query.php on line 724

all was fine for several weeks then this