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<front>
<journal-meta>
<journal-id journal-id-type="publisher">EGUsphere</journal-id>
<journal-title-group>
<journal-title>EGUsphere</journal-title>
<abbrev-journal-title abbrev-type="publisher">EGUsphere</abbrev-journal-title>
<abbrev-journal-title abbrev-type="nlm-ta">EGUsphere</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub"></issn>
<publisher><publisher-name>Copernicus Publications</publisher-name>
<publisher-loc>Göttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/egusphere-2026-4779</article-id>
<title-group>
<article-title>Preservation of Glaciochemical Signals in a Warming Tropical Ice Cap: Evidence from the 2022 Quelccaya Ice Core</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Gomes Ilha</surname>
<given-names>João</given-names>
<ext-link>https://orcid.org/0000-0001-6188-0126</ext-link>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Brum Poitevin Portella</surname>
<given-names>Manoela</given-names>
<ext-link>https://orcid.org/0000-0002-9758-6743</ext-link>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
<xref ref-type="aff" rid="aff4">
<sup>4</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Vilca Gomez</surname>
<given-names>Oscar</given-names>
</name>
<xref ref-type="aff" rid="aff5">
<sup>5</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Gaudie Lindau</surname>
<given-names>Filipe</given-names>
<ext-link>https://orcid.org/0000-0001-7603-7203</ext-link>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Potocki</surname>
<given-names>Mariusz</given-names>
</name>
<xref ref-type="aff" rid="aff6">
<sup>6</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Barbaro</surname>
<given-names>Elena</given-names>
<ext-link>https://orcid.org/0000-0003-2639-7475</ext-link>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Kaspari</surname>
<given-names>Susan</given-names>
</name>
<xref ref-type="aff" rid="aff4">
<sup>4</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Barbante</surname>
<given-names>Carlo</given-names>
<ext-link>https://orcid.org/0000-0003-4177-2288</ext-link>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Cardia Simões</surname>
<given-names>Jefferson</given-names>
<ext-link>https://orcid.org/0000-0001-5555-3401</ext-link>
</name>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Mayewski</surname>
<given-names>Paul Andrew</given-names>
</name>
<xref ref-type="aff" rid="aff6">
<sup>6</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Department of Environmental Sciences, Informatics and Statistics, Ca’ Foscari University of Venice, Venice, Italy, 155 Via Torino, 30172 Venezia Mestre, Italy</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>CNR – Institute of Polar Sciences (ISP-CNR), 155 Via Torino, 30172 Venezia Mestre, Italy</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>Polar and Climate Center (CPC), Instituto de Geociências, Universidade Federal do Rio Grande do Sul (UFRGS), Av. Bento Gonçalves, 9500, 91501-970, Brasil</addr-line>
</aff>
<aff id="aff4">
<label>4</label>
<addr-line>Department of Geological Sciences, Central Washington University, Ellensburg, Washington, WA, 98926, USA</addr-line>
</aff>
<aff id="aff5">
<label>5</label>
<addr-line>Oficina Desconcentrada Macro Región Sur, Instituto Nacional de Investigación en Glaciares y Ecosistemas de Montaña (INAIGEM), Cusco, Peru</addr-line>
</aff>
<aff id="aff6">
<label>6</label>
<addr-line>Climate Change Institute (CCI), University of Maine, Orono, ME, 04469-5790, USA</addr-line>
</aff>
<pub-date pub-type="epub">
<day>23</day>
<month>09</month>
<year>2026</year>
</pub-date>
<volume>2026</volume>
<fpage>1</fpage>
<lpage>28</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2026 João Gomes Ilha et al.</copyright-statement>
<copyright-year>2026</copyright-year>
<license license-type="open-access">
<license-p>This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit <ext-link ext-link-type="uri"  xlink:href="https://creativecommons.org/licenses/by/4.0/">https://creativecommons.org/licenses/by/4.0/</ext-link></license-p>
</license>
</permissions>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2026/egusphere-2026-4779/">This article is available from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-4779/</self-uri>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2026/egusphere-2026-4779/egusphere-2026-4779.pdf">The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2026/egusphere-2026-4779/egusphere-2026-4779.pdf</self-uri>
<abstract>
<p>Paleoclimate records stored in ice cores are facing great threat as on-going mass loss is rapidly accelerating. To study Amazon&amp;rsquo;s paleoclimate, an ice core was drilled in the Quelccaya ice cap, in Peru, in 2022. However, as a first step, post-depositional alterations need to be discussed and described. During drilling, one water table (WT) associated with the firn-ice transition and a major fracture at 45 m depth were identified. Here we present the first chemical results retrieved from the ice core and discuss the preservation state of the record in terms of post-depositional alterations. Concentrations of levoglucosan, Na&lt;sup&gt;+&lt;/sup&gt;, K&lt;sup&gt;+&lt;/sup&gt;, Cl&lt;sup&gt;&amp;minus;&lt;/sup&gt;, SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2&amp;minus;&lt;/sup&gt; and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;&amp;minus;&lt;/sup&gt; were analyzed and compared with the relatively insoluble and immobile black carbon signal. Furthermore, signal preservation was evaluated using descriptive statistics, covariance analysis, ionic balance, and multivariate classification. Statistical analyses reveal enhanced ion concentration atop the WT. The section below the WT extending to the fracture is marked by a highly altered chemical signal, as indicated by multivariate analysis. Within this interval, Cl&lt;sup&gt;&amp;minus;&lt;/sup&gt; is strongly depleted and Na&lt;sup&gt;+&lt;/sup&gt; shows increased association with SO&lt;sub&gt;4&lt;/sub&gt;&lt;sup&gt;2&amp;minus;&lt;/sup&gt; and NO&lt;sub&gt;3&lt;/sub&gt;&lt;sup&gt;&amp;minus;&lt;/sup&gt;, while the ionic balance indicates increased acidity relative to the WT onset. Below the fracture, chemical signals are attenuated but largely preserved. Principal Component Analysis coupled to Fuzzy C-Means clustering independently identifies the WT, altered ice interval, the fracture zone and a deep ice anomaly, suggesting variable preservation along the core. We define depth intervals characterized by preserved, amplified, altered and attenuated signals and show that despite significant meltwater influence, post-depositional alterations are locally concentrated rather than affecting the entire record. These results provide a basis for future paleoclimatic investigations using what could be the last Quelccaya Ice Cap ice core before continued melting irreversibly alters the record.</p>
</abstract>
<counts><page-count count="28"/></counts>
<funding-group>
<award-group id="gs1">
<funding-source>National Science Foundation</funding-source>
<award-id>P2C2 AGS-1600018</award-id>
</award-group>
<award-group id="gs2">
<funding-source>Conselho Nacional de Desenvolvimento Científico e Tecnológico</funding-source>
<award-id>465680/2014-3</award-id>
<award-id>422695/2021-1</award-id>
</award-group>
</funding-group>
</article-meta>
</front>
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