纪晨和我是中科院研究生院时的同学，后来在加州理工时又是同学。彼此比较熟悉，大同行。

征得他的同意，把我们这两天部分邮件沟通摘录如下，因为所涉及的讨论是值得展示的。1）对于很简单的问题，我们都存在不同观点，但这在科学探索，任何一个学科中都是蛮常见的现象，更何况我们对地震这一自然现象的了解真的是很初级。2）网上对沈正康老师的攻击让人觉得悲哀，这样没有专业背景且伤人的行为能有什么好处呢？对从事地震研究的人展开攻击除了政治目的和发泄情绪，还有多大的好处呢？3）我们发声真的很弱，我们的沟通能力和愿望真的是很弱。或许我这是在自找麻烦。。。

由于他敲中文太慢（我也好不到哪去），我们的邮件往往是英文的。时间缘故，恕不翻译。

纪：

Hi, Jiuhui and Jing

How are you?

I received this request today but didn't response as I smell some politics inside. But it

does make me curious about why the folks in your institute (also CEA) insist this is not an aftershock???

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刘：

Hi Chen,

we have been debating among ourselves whether it is an aftershock, or a standalone quake, regardless of the positive static stress influence. i guess the public is more interested in the implication of whether it is an aftershock or not, rather than a pure scientific quest.

Jiuhui may disagree with me and probably you too, but my opinion is both yes and no. yes, in the sense that by one aftershock definition, events occur within one rupture length distance from the mainshock fault in the years after the main shock can be considered as aftershocks. The definition treats earthquakes as faceless statistics. no, in the sense, that different structure (i believe a reverse fault was activated, basinward from those broke in 2008 wenchuan eq) in Lushan earthquake, and it has its own aftershock sequence with abnormally high number so far. i am more inclined to the second opinion.

i am surprised that XX is indeed strongly opinionated and biased. what good will it do to play the blame game? many people are like this. people doing earthquake research in China are like rats in the street. this appears to be our destiny, sadly.

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纪：

Jing, ok, this reminds me the debate when Morgan Page presented her results at SCEC. Geophysicists and geologists view the aftershock differently. What I felt in watching this chaos is the lack of communication. CEA should put the definition of aftershocks online. I also read an article which blamed the work of Zhengkang without any scientific background.

Jiuhui also mentioned the abnormal aftershock sequence. As I heard, this rupture didn't break the surface. It is then very similar to 1994 Mw 6.7 Northridge earthquake. Another conclusion for that earthquake is the abnormal large damage, which seems to be also consistent with this earthquake. There is a hypothesis that blinding thrust will have larger damage than the similar size earthquakes which break the surface.

Hopefully this will help you in explaining this earthquake.

Chen

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刘：

Hi Chen, in fact I just wrote a sciencenet blog comparing the Lushan and northridge eq. you have a good point regarding the severe damage. We have similar thoughts about lack of voice in media communication. Most of my colleagues, including myself, are either afraid of or reluctant in speaking out.