Brand new to preprints? Check out this introductory video from ASAPBio
How will submitting a preprint help me/others?

You will be able to share your work with colleagues months, even years, before you would had you submitted only to a peer-reviewed journal. The peer-review process takes time, and during that time you are without a citable manuscript to share. Preprints are citable and shareable immediately after submission. Many authors have found that sharing a preprint maintains enthusiasm about the research and leads to helpful feedback, which makes the ultimate submission to a peer-reviewed journal better. The early and continued attention also has another payoff: Preprints that do end up in journals appear to be cited more quickly.

Because preprints can be cited, they can help early career scientists quickly build a scholarly track record. This can benefit people who are seeking funding or a job. Many funding agencies now allow preprint citations in grant proposals.

Preprints can also benefit both young and established researchers by providing more access to their work. Many peer reviewed journals require subscription charges that are prohibitive to some institutions. By placing your research on an open and freely available preprint system, anyone in the world can discover your work.

Are EarthArXiv preprints indexed by Google Scholar
Yes. And you can read about it here.
How might preprints and post-prints (peer reviewed articles) affect citations?
When you submit a manuscript to EarthArXiv a Digital Object Identifier (DOI) will be created and the preprint will become publicly accessible via the service. You will be unable to delete the preprint file, but you can update or modify it. When (if) the manuscript passes through peer review you can modify your preprint page to also include the DOI of the peer reviewed article. The preprint and the peer reviewed article are considered distinct works - thus, unique DOIs - and citations can be made to either. Generally, authors will cite, and encourage others to cite, the peer-reviewed version when/if available. However, you should be aware that the full set of citations to your research may include citations of the preprint and citations of the peer reviewed article. Services such as Google Scholar do not currently merge these citation counts.
Can I submit related matrials along with my paper, e.g. data and code?
Yes. Authors will get an email upon manuscript submission directing them to a project page that holds the preprint. On this project page authors can upload any supplemental materials. There is no cap on total storage or number of files as long as it is for research purposes. The only limit is a 5GB per file upload limit. Alternatively, if authors already have materials stored elsewhere, the project page allows for connections to be make to dropbox, box, google drive, github, gitlab, bit bucket, amazon s3, dataverse, figshare, and several other related storage providers. In addition, because EarthArXiv is built on top of the Open Science Framework (OSF) software, authors can also easily connect preprint submissions to files in an existing OSF project.
Does EarthArXiv offer free-text search of preprints?
Not at this time. This is a highly requested feature and on the future roadmap. However, given the multiple formats in which papers can be uploaded and the resources needed to conduct such searches, this is not something that we can offer right away.
Why have multiple preprint systems like PaleoArXiv and EarthArXiv? Why not just one?
Actually, the Center for Open Science is continually indexing and providing a common search interface over a number of preprint services accross several domains. Many of these preprint systems leverage the same technical infrastructe, so, in a way, there is one preprint system. Sites like EarthArXiv just provide a tailored view of a subset of the preprint ecosystem. EarthArXiv also adds promotion of preprints and community building specific to the Earth sciences. In the end, though, many of these systems are commonly indexed, share technology, and do exist as one big searchable preprint system.
Does EarthArXiv have plans for publishing talks and posters?
Talks and posters are very valuable resources and should be captured. Yet, talks and posters are fundamentally different than manuscript preprints and require a different set of concerns. Optical character recognition, extracting figures, and viewing posters on mobile devices are not easy challenges to overcome. EarthArXiv is hesitant about conflating posters and papers in one system given the varying technical requirements and volumes - the number of talks and posters far outweights the number of manuscripts. For these reasons, EarthArXiv is starting off with a focus only on manuscripts. We want to do preprint manuscripts - along with associated data and code - and do them well. As our system and community evolve, we may revisit poster and talk archiving. But, at this time, our focus is on manuscript preprints.
Isn't the American Geophysical Union launching a preprint service? And related questions:
Did you know this was coming?
Yes, we did. Several of us at EarthArXiv have been having discussions with AGU and they had mentioned it was coming. Although, we didn’t some of the details until we saw the official release announcement. AGU has been open about their preprint intentions to the extent possible given their ongoing negotiations with Wiley. In particular, the AGU Senior Vice President, Publications, Brooks Hanson, has been in contact with our group several times in attempts to bring numerous societies, archives, and interested groups to the table to discuss preprint topics.
Does this change your plans for EarthArXiv?

No, this doesn’t change our plans. Many within EarthArXiv have fundamental philosophical concerns with AGU's technical implementation plan. We favor a completely open approach independent of any publishers. We would like a community-led, transparent, and open source effort. The AGU approach is a contract with a major publisher and is built on top of proprietary software. This is not a specific criticism of AGU or Wiley. Publishers should be part of the discussions. Yet, it raises questions about the long term nature of the system when a publisher, any publisher, is doing the development. Questions that we think can be avoided by being open source and independent from the start.

We want to involve publishers in our preprint efforts. Yet, we think a vibrant ecosystem of advances emerges when the implementation of the preprint system is independent of any one publisher, the software is open source, and there is an open advisory/governance model. It remains to be seen to what extent, if at all, the community will be able to extend the AGU/Wiley Atypon system.

Is this the end of AGU and EarthArXiv working together?
No. Not at all. Even though we disagree on the technical infrastructure, we very much agree with AGU on the need to bring all interested parties to the table to discuss best practices and higher level issues surrounding preprints. We continue to try to engage AGU in these discussions.We are going to pursue different implementations of our ideas, but we hope to continue to work together on best practices in preprint publishing.
Is there now a competition between ESSOAr and EarthArXiv?
The AGU's Earth and Space Science Open Archive (ESSOAr) presents an alternative place to publish. In that regard, we will compete for papers. But, we view it more as this is how science works. Anyone is able to put their ideas out there for debate, testing, and validation. We differ with AGU over implementation and we are offering the community an alternative. Now we'll have to wait and see what they think.