[Realtime-feeds] Feed JSON field question

[Matt Keller]

One last field question regarding the ID of each event. The geoJSON
glossary for the realtime-feed states that the {features:[id: String]}
field is the unique identifier for the event. It states, however, that the
ID may change over time. It then refers to the {features:[properties: {ids:
String}]} field for all of the IDs associated with an event. How does this
actually play out in the feed in real life? Lets say an earthquake happens
with the ID of 1. This shows up in both the ID and the properties:IDs
field. How/when would the ID change? I get that the new ID would be added
to the list of IDS. I just don't understand why the original ID would
change.

For my application, i just need to track an event with some kind of unique
identifier. I would not want to duplicate the event if the ID suddenly
changed. I'm just curious how the process works and if i need to worry
about it. I might also mention that i'm only monitoring the all_hour feed.
So it may not be a huge deal for that particular feed.

Thanks again for everyone's input. As a programmer (and not a scientist),
this information has helped a lot.


On Tue, Apr 15, 2014 at 11:58 AM, Renate Hartog <jrhartog at uw.edu> wrote:

> For completeness sake, not only the California regional networks submit
> their near-real time automatic solutions to the NEIC, several others do as
> well.  For example, the Pacific Northwest Seismic Network (PNSN), which
> covers Washington and Oregon State also does. We do use some quality
> criteria that have to be met before an automatic solution gets sent, among
> other things, it has to have an initial magnitude estimate of 1 or bigger.
> If it does not meet those very basic requirements, the solution won't get
> sent until someone actually reviews it.  Our automatic solutions should
> show up within about 5 minutes of the origin time of the earthquake. We do
> have fewer earthquakes than in California, so they may not show up in the
> real-time feeds very frequently.
>
> -Renate (research staff at PNSN)
>
>
> On Mon, Apr 14, 2014 at 4:16 PM, Earle, Paul <pearle at usgs.gov> wrote:
>
>> Matt,
>>
>> California has more seismic stations and post automatic solutions. Most
>> other regions in the U.S. do not post automatics.
>>
>> regards,
>> Paul
>>
>>
>> On Mon, Apr 14, 2014 at 5:13 PM, Matt Keller <mattrk at mattrk.com> wrote:
>>
>>> Eric,
>>>
>>> That's exactly what I needed to know. Thanks for clearing that up.
>>>
>>> Out of curiosity, do you know why the data for areas outside of
>>> California is delayed up to 30 minutes while California data is posted
>>> within a just a few minutes? I understand that California has more
>>> earthquakes than anywhere else and needs faster notifications but i was
>>> just curious why this is from a technical side. Is this data prioritized
>>> somehow? Or are you simply polling that equipment more often?
>>>
>>> Thanks again.
>>>
>>>
>>> On Mon, Apr 14, 2014 at 9:06 AM, Martinez, Eric <emartinez at usgs.gov>wrote:
>>>
>>>> Hi Matt,
>>>>
>>>> The time field under features > properties corresponds to the *time at
>>>> which the earthquake occurred*.
>>>>
>>>> The updated field under features > properties corresponds to the time
>>>> the most recent update arrived. This can be driven by any preferred
>>>> associated product (for example, the arrival of a ShakeMap product can
>>>> affect the updated property).
>>>>
>>>> Updated earthquakes are *not* re-added to the past hour or past day
>>>> feeds. Each feed for a given time period contains earthquakes that occurred
>>>> within that time period. Subsequent updates to earthquake information do
>>>> not affect what earthquakes appear in the feeds.
>>>>
>>>> Regards,
>>>>
>>>> Eric Martinez
>>>> U.S. Geological Survey
>>>> emartinez at usgs.gov
>>>>
>>>>
>>>> On Fri, Apr 11, 2014 at 8:07 PM, Matt Keller <mattrk at mattrk.com> wrote:
>>>>
>>>>>  Does the time field under features > properties correspond to the
>>>>> time at which the earthquake occurred or the time at which the earthquake
>>>>> was posted to the feed? From what I've read, earthquakes that happen in
>>>>> other parts of the country (Not California) can be posted as much as 30
>>>>> minutes after the fact. I'm wondering what the time stamp actually means.
>>>>>
>>>>> Additionally, are "updated" quakes re-added to the past hour or past
>>>>> day feeds if they are updated significantly later? E.g. When a quake that
>>>>> happened 26 hours ago is updated, Is that quake re-added to the past
>>>>> hour/past day feed? I would assume not, but i wanted to verify. I'm
>>>>> assuming that the data for that particular quake is simply updated and the
>>>>> "updated" field is just incremented.
>>>>>
>>>>> Thanks
>>>>>
>>>>> _______________________________________________
>>>>> Realtime-feeds mailing list
>>>>> Realtime-feeds at geohazards.usgs.gov
>>>>> https://geohazards.usgs.gov/mailman/listinfo/realtime-feeds
>>>>>
>>>>>
>>>>
>>>
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>>>
>>>
>>
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>>
>
>
> --
> Renate Hartog
> Research Scientist
> Pacific Northwest Seismic Network
> Department of Earth and Space Sciences
> University of Washington
> Box 351310
> Seattle, WA 98195
>
> Tel. +1-206-685-7079 (office)
>
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