You can use PowerShell to export alerts from SCOM 2010 to a CSV file with lots of information included. Please note, exported alerts are listed in Greenwich Mean Time (GMT) time zone.
#Closed Critical Alerts
get-scomalert -criteria ‘ResolutionState=255 AND Severity>=2’ | select MonitoringObjectDisplayName,Name,Severity,ResolutionState,TimeRaised,TimeResolved,Parameters | export-csv c:\ClosedCriticalAlerts.txt
#New Critical Alerts
get-scomalert -criteria ‘ResolutionState=0 AND Severity>=2’ | select MonitoringObjectDisplayName,Name,Severity,ResolutionState,TimeRaised,Parameters | export-csv c:\NewCriticalAlerts.txt
#New Warning Alerts
get-scomalert -criteria ‘ResolutionState=0 AND Severity>=2’ | select MonitoringObjectDisplayName,Name,Severity,ResolutionState,TimeRaised,Parameters | export-csv c:\NewWarningAlerts.txt
Resolution State
0 = New
255 = Closed
Severity Values for Alerts
0 = INFORMATIONAL
1 = WARNING
2 = CRITICAL
Marc Kean 
Good post. I learn something totally new and challenging on blogs I stumbleupon on a
daily basis. It will always be exciting to read through content
from other writers and use something from other sites.
Thanks for the good post, I had to adapt a little for scom2012 to get it worked but it gave me the basic information I needed to export the alerts from scom. Scom2012 use: “-resolutionstate 0” and “-resolutionstate 255”.