Talk:Heinrich event/Archive 1

Archive 1

Changes

I've made some changes, some of which undo some of Wetmans changes (sorry). As far as I can tell, HE's are very specific things as far as the glacios are concerned, and there are 6 of them. They aren't the same as D-O events and they aren't the same thing as the more recent shorter cycles. Also I'm a bit unclear in which way H3 and H6 are different but I think its not just in terms of their sources. William M. Connolley 21:06, 23 September 2005 (UTC).

I've added some external links, so that a reader who finds the present article insufficient and inconclusive may read some recent science on the subject. --Wetman 00:01, 24 September 2005 (UTC)

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Hemming (2004) reports that there is little published evidence for Heinrich events in previous glacial periods, though Stokes may beg to differ in the 2005 edition of Global and Planetary Change. Moved the italicized addition here. Anyone want to render this obscure hint relevant? --Wetman 17:12, 7 November 2005 (UTC)

No idea. Was intending to try to find out... might be [1] William M. Connolley 17:54, 7 November 2005 (UTC). Oh, and if it *is* that then we should leave it out: its still in press. Unless we're into really topical science, we shouldn't be including stuff within a year of publication really. William M. Connolley 17:56, 7 November 2005 (UTC).

BTW, Heinrich events are related to, but not the same as, Dansgaard-Oeschger events is, I agree, unsatisfactory. I shall try to improve that. William M. Connolley 17:50, 7 November 2005 (UTC).

Hodell et al, Palaeoceanography vol 23(PA4218)December 2008 provide detailed evidence of Heinrich events (detected using Si/Sr ratios and other XRF-based proxies) in previous glacials going back to at least 640 ka in the North Atlantic (Site IODP U1308). Interestingly, there is "a pronounced change" in the "composition and frequency of IRD" at this time, which is approximately coincident with the change from a 41 kyr (orbital obliquity) to a 100 kyr (probably orbital eccentricity) dominated climate regime. The absolute size of the ice sheets developed at this time may have played a role in these changes, but the authors point out that more sites need to be studied at this level of resolution. Orbitalforam (talk) 12:21, 7 January 2009 (UTC)

Incidentally, studies such as Hodell's indicate that this remark in the article is incorrect: "Heinrich events are observed during the last glacial period; the low resolution of the sedimentary record before this point makes it impossible to deduce whether they occurred during other glacial periods in the Earth's history". Hemming, in Reviews of Geophysics,42, RG1005, doi:10.1029/2003RG000128, 2004 also discusses evidence of Heinrich events prior to the last glacial (ie before about 130 kyr BP).Orbitalforam (talk) 15:27, 31 March 2010 (UTC)

Popularized explanation

It would be nice to add popular-science-like explanation into introduction part of the article, here and for Dansgaard-Oeschger event as well. Readers would appreciate it. 02:21, 17 November 2005 (UTC)

Hemming 2004

Where have the ages for the Heinrich events been taken from? They don't appear in the article.

The dates are sourced in the table. I can't remember if Hemming states them explicitly or if I had to read them off a graph. William M. Connolley 15:46, 21 December 2005 (UTC).

August 2006

There is an easy answer to Conolley's question. The mineral assemblage of H1,2,4,5 ist different from H3 and H6. The latters are characterized by higher amounts of the clay mineral smectite (weathering product of volcanic rock) and volcanic glass shards. All this points to a stronger supply of ice from the Norwegian-Greenland Sea area. Whereas H1,2,4, and 5 have mineral assemblages of the Laurentian region.[User: Hartmut Heinrich, 10 Aug 2006]

Richard Alley's estimate on the volume of ice discharged during a H event (370 km³) seems by far too small. New investigations (satellite gravimetry) report an annual loss from Greenland of about 230 km³ due to the present climate warming. Are we "enjoying" a H event? :-)[User: H Heinrich, 11 Aug 2006]

Good spot H. The actual figure is 370 000 000 000 km³… Verisimilus T 18:58, 7 May 2007 (UTC)

Coiuld use some clarification

This phrase is confusing. Perhaps it makes sense if you already know something about Heinrich events, but why wouldn't H3 and H6 be "different"? If they were the same, wouldn't they have the same name?

Six such events, labelled H1-H6, have been identified. There is some evidence that H3 and H6 are different.

Some context would help readers understand just how much the volume of water below is; is there something to which we can compare it?

the volume of freshwater discharged by a typical Heinrich event as 370 km3

Also, what's a "glacial"? An ice age? Clarifying that, and linking to an appropriate Wikipedia article, would help.

Most importantly, what characterizes a Heinrich events? Anything beyond lots of icebergs and fresh water? —The preceding unsigned comment was added by 66.92.53.49 (talk • contribs) .

I added a link to the "last glacial" which is hard to name as it has different names in different part of the world - see the link in this very sentence. I also added a sentence on the possible sources of the water discharge. I believe that otherwise the definition in the article is well done. Friendly Neighbour 10:51, 19 September 2006 (UTC)

Failed GA Nomination

This is a good article but it has some issues which will take a while to fix.

- Article needs a lot more references. I don't mean as in more references being used but as the facts currently in the article need to be sourced.

-I could not understand the lead section. I think it needs a complete rewrite to make it understandable to those who know little about the topic. It also needs to be made into two or three paragraphs.

- The section heading "H3 & 6 - Heinrich events?" needs to be changed. Usually questions are not put as section headings and according to the Manual of Style the word "and" should be written out.

- There are a few one sentence paragraphs which need to merged or cut.

- In the External Forces section several words are in bold. I could not figure out why.

- In the internal Forces section, the word not is in itallics.

I hope someone will resubmit this article. It is close! --Banana 02:26, 26 May 2007 (UTC)

Hi, many thanks for your review and constructive feedback!

I've had a look at the article and made a few changes, and will continue to make more.

However, I'd quite like to keep the bolding of the different explanations, as I think it makes reading clearer, especially to a skim-reader. It seems to be legit with the MOS - see this page, which admittedly uses bulleted points.

And whilst I've removed the italics from "not", I think this makes reading a little easier, too, emphasising the difference. Do I have to get rid of it?

Thanks, Verisimilus T 10:34, 26 May 2007 (UTC)

Though I avoid the jury process and don't care whether this good article is a "Good Article" or not, I have some suggestions to make this fine presentation more user-friendly. Nordic Sea is an unfamiliar term: is the Norwegian Sea intended? Hartmut Heinrich: introduce him, as formerly, as soon as the reader is asking "Why 'Heinrich'"? "Density-driven circulation": identify it as identical to the thermohaline circulation. The specialized vocabulary always needs to be given an unobtrusive phrase in apposition at its first appearance: alkenone, speleothem, aren't in the usual reader's vocabulary: what if the reader is asking "What's a lithic?" Most of the bulleted items can be expanded, not to be so gnomic: ask "why is this so?" at each instance. Writing out Thorium-230 is friendlier. --Wetman 11:06, 26 May 2007 (UTC)

Review

This is a well written, well sourced and comprehensive article. The only issue, that I have with it, is the lead section. It should provide a summary of the article and not to introduce any data that are not mentioned in the main text. For instance, the second paragraph should be moved to a different section as it defines the volume of fresh water. Some information in the third paragraph is also not mentioned in the main text. In addition the main text lacks any definition of Heinrich events themselves, it is only present in the lead. I hope that the lead section can be rewritten quickly so I can promote the article to GA status. Ruslik 10:41, 21 June 2007 (UTC)

Thanks for your thoughts. I'll take a proper look at re-structuring the article when I'm feeling a little better! Verisimilus T 11:21, 21 June 2007 (UTC)

I've moved some bits of the lede into the article. I feel that the first two paragraphs of the Diagnosis section now give a suitable explanation of what a H event is, but am open to your thoughts. Thanks again for your review, hope you find this okay! Verisimilus T 14:26, 24 June 2007 (UTC)

The lead is OK now. However I don't see any definition like: "Heinrich events are defined as periods during the last glacial period when vast amounts of ice in the form of icebergs were dumped into the North Atlantic." or smth like this. In addition it may be useful to move the "Timing" section to the beginning of the article and to start it with this definition. The current position of the "Timing" section seems a bit odd. It'd be better to define the events, then provide their timings and then discuss diagnostics etc. Ruslik 18:07, 25 June 2007 (UTC)

Since there is no answer I agree that the article has failed GA. Ruslik 11:33, 28 June 2007 (UTC)

Sorry, been a bit busy. Will fix presently - is it alright if I get in touch with you once I've done it and you reconsider it for GA then? Cheers. Verisimilus T 11:44, 28 June 2007 (UTC)

Please also add some inline citations. Quite important in a GA. Anonymous Dissident^Talk 11:46, 28 June 2007 (UTC)

There are several inline citations already present in the article. See WP:CITE#Harvard_referencing.

Unfortunatly, I have already removed it from the list of candidates. However it you do the job and renominate it I will review this article again. Ruslik 11:59, 28 June 2007 (UTC)

Thanks! Verisimilus T 12:32, 28 June 2007 (UTC)

...and now Verisimilus sees the difference between this and the peer review process, with which V. is familiar. --Wetman 18:12, 28 June 2007 (UTC)

— Verisimilus T 18:25, 28 June 2007 (UTC)

Review (2)

Since my suggestions from the previous review (see above) have been taken into account, now I think that the article passes GA. Ruslik 08:58, 29 June 2007 (UTC)

Hooray! Thanks for taking the time to review this article and provide feedback. Verisimilus T 13:08, 29 June 2007 (UTC)