活动变更或到期

当某个提醒发生更改时，请发出一个指向该提醒的新提醒。请勿更改或移除 Feed 中的现有提醒。在适当时间（如 24-48 小时）后，从 Feed 中移除“已取消”、“已更新”或“已过期”的提醒。

您可以通过以下方式处理事件变更或过期：

• UPDATE 或 CANCEL <msgType> 必须包含至少一个 <references> 元素。
• 您可以通过三种方式取消事件（按优先级顺序）：
  1. 为每个事件设置 <expires> dateTime 值。在消息说明中，您可以设置此提醒的预期结束状态。
  2. 不久后发出新的 <alert> 消息，其中包含 <msgType> UPDATE、<responseType> "All Clear" 和 <expires>。
  3. 发出带有 <msgType> CANCEL 的新 <alert> 消息。在 <references> 元素中，请参阅要取消的原始提醒。

示例

<alert xmlns="urn:oasis:names:tc:emergency:cap:1.2">
  <identifier>PAAQ-4-mg5a94</identifier>
  <sender>[e-mail]</sender>
  <sent>2013-01-05T10:58:23-00:00</sent>
  <status>Actual</status>
  <msgType>Update</msgType>
  <source>WCATWC</source>
  <scope>Public</scope>
  <code>IPAWSv1.0</code>
  <references>[e-mail],PAAQ-1-mg5a94,2013-01-05T09:01:16-00:00
   [e-mail],PAAQ-2-mg5a94,2013-01-05T09:30:16-00:00 [e-mail],
   PAAQ-3-mg5a94,2013-01-05T10:17:31-00:00</references>
  <incidents>mg5a94</incidents>
  <info>
    <category>Geo</category>
    <event>Tsunami Cancellation</event>
    <responseType>None</responseType>
    <urgency>Past</urgency>
    <severity>Unknown</severity>
    <certainty>Unlikely</certainty>
    <onset>2013-01-05T10:58:23-00:00</onset>
    <expires>2013-01-05T10:58:23-00:00</expires>
    <senderName>NWS West Coast/Alaska Tsunami Warning Center Palmer
     AK</senderName>
    <headline>The tsunami Warning is canceled for the coastal areas of
     British Columbia and Alaska from the north tip of Vancouver Island,
     British Columbia to Cape Fairweather, Alaska (80 miles SE of
     Yakutat).</headline>
    <description>The tsunami Warning is canceled for the coastal areas of
     British Columbia and Alaska from the north tip of Vancouver Island,
     British Columbia to Cape Fairweather, Alaska (80 miles SE of Yakutat).
     - Event details: Preliminary magnitude 7.5 (Mw) earthquake / Lat:
     55.300, Lon: -134.900 at 2013-01-05T08:58:20Z Tsunami cancellations
     indicate the end of the damaging tsunami threat. A cancellation is
     issued after an evaluation of sea level data confirms that a
     destructive tsunami will not impact the alerted region, or after
     tsunami levels have subsided to non-damaging levels.</description>
    <instruction>Recommended Actions: Don't re-occupy hazard zones until
     local emergency officials indicate it is safe to do so. This will be
     the last West Coast/Alaska Tsunami Warning Center message issued for
     this event. Refer to the internet site ntwc.arh.noaa.gov for more
     information. </instruction>
    <web>http://ntwc.arh.noaa.gov/events/PAAQ/2013/01/05/mg5a94/4/WEAK51/WEAK51.txt</web>
    <parameter>
      <valueName>EventLocationName</valueName>
      <value>95 miles NW of Dixon Entrance, Alaska</value>
    </parameter>
    <parameter>
      <valueName>EventPreliminaryMagnitude</valueName>
      <value>7.5</value>
    </parameter>
    <parameter>
      <valueName>EventPreliminaryMagnitudeType</valueName>
      <value>Mw</value>
    </parameter>
    <parameter>
      <valueName>EventOriginTime</valueName>
      <value>2013-01-05T08:58:20-00:00</value>
    </parameter>
    <parameter>
      <valueName>EventDepth</valueName>
      <value>5 kilometers</value>
    </parameter>
    <parameter>
      <valueName>EventLatLon</valueName>
      <value>55.300,-134.900 0.000</value>
    </parameter>
    <parameter>
      <valueName>VTEC</valueName>
      <value>/O.CAN.PAAQ.TS.W.0001.000000T0000Z-000000T0000Z/</value>
    </parameter>
    <parameter>
      <valueName>NWSUGC</valueName>
      <value>BCZ220-210-922-912-921-911-110-AKZ026&gt;029-023-024-019&gt;
      022-025-051258-</value>
    </parameter>
    <parameter>
      <valueName>ProductDefinition</valueName>
      <value>Tsunami cancellations indicate the end of the damaging tsunami
       threat. A cancellation is issued after an evaluation of sea level
       data confirms that a destructive tsunami won't impact the alerted
       region, or after tsunami levels have subsided to non-damaging
       levels.</value>
    </parameter>
    <parameter>
      <valueName>WEAK51</valueName>
      <value>Public Tsunami Warnings, Watches, and Advisories for AK, BC,
       and US West Coast</value>
    </parameter>
    <parameter>
      <valueName>EAS-ORG</valueName>
      <value>WXR</value>
    </parameter>
    <resource>
      <resourceDesc>Event Data as a JSON document</resourceDesc>
      <mimeType>application/json</mimeType>
      <uri>http://ntwc.arh.noaa.gov/events/PAAQ/2013/01/05/mg5a94/4/WEAK51/PAAQ.json</uri>
    </resource>
    <area>
      <areaDesc>95 miles NW of Dixon Entrance, Alaska</areaDesc>
      <circle>55.3,-134.9 0.0</circle>
    </area>
  </info>
<Signature xmlns="http://www.w3.org/2000/09/xmldsig#">
  ...
</Signature>
</alert>